FAQ

General Questions

Is there an integrated help function available in GMG OpenColor?

No, but you can access our GMG OpenColor Help Center on the internet directly from the software. To do so, please click on the gear icon at the top right and select Help.... This will open the Help Center start page in your default browser.

What is the definition of "multicolor"?

In a multicolor workflow, the standard CMYK ink set is extended with additional colors, thus enhancing the color space. Especially the 7-ink combination CMYK + OGV, i.e. the additional use of orange, green, and violet, can be very beneficial. With these seven inks, you can cover a very wide range of spot colors without changing inks on the press.

Although multicolor workflows are particularly appreciated in commercial and art printing, they offer clear advantages in other areas as well:

  • The enhanced color space, also called ECG from Enhanced Color Gamut, enables print products more true-to-original.
  • Your pictures will be richer in contrast due to increased luminosity and saturation.
  • Separated spot colors are better reproduced, so that you can also display extreme product colors with colorimetric accuracy.
  • You save time and money, because no process color needs to be changed and no ink unit needs to be cleaned when spot colors are requested.

There are also multicolor workflows with less or more than 7 inks.

Why does the spot color on my proof differ visually from the Pantone® color guide?

Printed Pantone® color guides, like all printed products, are subjects to production fluctuations and age-related color changes. They are thus not a reliable reference for comparison.

GMG OpenColor and GMG SpotColor Editor use the manufacturer's official target values for spot color calculation. If a spot color has been verified on GMG Spot Color Control Strip 2.0 with low dE values, you can thus rely on it being reproduced correctly, even if the result may differ visually from your color guide.

Download & Installation

Where can I find the latest GMG OpenColor version?

You can find the current version in our download center under https://gmgcolor.com/support/download/product/opencolor/.

Where can I find the GMG OpenColor manual?

During the installation, the user guide is saved as a PDF file in your GMG OpenColor folder automatically. You can also download the manual as well as further documentation from our tutorial page under the following link: Tutorials

How can I uninstall GMG OpenColor completely?

By following the steps below, you can remove GMG OpenColor and all its components. This also includes configuration files such as measurements, characterizations, projects, and profiles. If you would like to install and use GMG OpenColor later again, we recommend you to create an environment backup before uninstalling.
  1. Exit GMG OpenColor completely.
  2. On the left side of your Windows task bar, click the button Start and choose Settings > Apps > Apps & features.

    A list of all your installed applications opens.

  3. Choose the entry GMG OpenColor [Version] and click the button Uninstall.
  4. In your file manager, open the directory C:\Program Files\GMG.
  5. Delete the folder GMG OpenColor.
  6. In your file manager, open the directory C:\ProgramData\GMG.
  7. Delete the folder OpenColor.

If you do also use other GMG solutions on your computer, the Uninstall is successfully finished at this point.

  1. In your file manager, open the directory C:\Program Files(x86).
  2. If available, delete the folder AppService.

The Uninstall is now successfully finished.

Network

Which ports and URLs are used by GMG OpenColor?

An overview of the ports and URLs used can be found on our website under the following link: Ports and URLs

Media

Why do I need to define the paper white point?

An adjustment of the paper white point is necessary to simulate the target colors on the actual substrate optimally and to avoid visible color shifts.

How can I define the paper white point?

If your original files do not contain a substrate value, you can either measure the substrate color or duplicate and adjust the substrate color from another, already existing characterization.

How can I measure the paper white point of my media?

If you have an integrated or externally connected measuring device, you can measure the substrate color under Database > Measure > Custom Patches.

Measuring

Which measuring conditions are available in GMG OpenColor?

In GMG OpenColor, the measuring conditions M0, M1, and M2 can be used.

What are the differences between M0, M1, and M2?

The measuring conditions differ primarily in their adaption to different viewing conditions. The modes each contain different UV light values.
  • M0 corresponds the measuring condition formerly known under the name without filter, where no UV light is filtered.
  • M1 corresponds the D50 5000K measuring condition, which contains a defined portion of UV light and is adapted to the viewing condition ISO3669:2009.
  • M2 corresponds the UV-Cut-Filter mode, which filters UV light completely.

When should I select which measuring condition?

With our solutions GMG ProofControl and GMG ProofControl Inline, the selection is done automatically, so you don't have to think about it. For the verification of existing standards, the mode defined in the given reference is automatically used.
In most cases, M1 is the right choice these days, as this mode is adapted to standardized viewing conditions according to ISO 3664:2009.

Which measuring device should I choose to cover as many measuring conditions as possible?

The measuring devices ILS30, i1 Pro2 and iSis 2 are all able to measure with M0, M1 as well as M2. Due to this flexibility, all of them can be recommended without restriction.

Which measuring condition is used for Pantone® databases?

The Pantone® databases in GMG OpenColor use the measuring condition M2 instead of M0 or M1, as in all our solutions. The advantage is consistency with Adobe® products, which all use M2 mode for Pantone® spot colors.

Which CxF versions are supported for measurement data import?

You can import spectral characterizations in Color Exchange Format 3, CxF3 for short. If the measurement data is available as a custom CxF/X‑4 resource according to ISO 17972‑4, spot color gradations are also taken into account by GMG OpenColor.

The universal Color Exchange Format (CxF) was developed by X‑Rite and officially accepted as an ISO standard. Being an open format, it enables the precise communication of digital standards, measurement data, and metadata across different applications.

While a regular CxF3 file contains only information on solid colors, a custom CxF/X‑4 resource can also provide information on gradations. GMG OpenColor supports the import of such CxF/X‑4 resources and can thus also take into account existing data on spot color gradations.

You can find further information on these user-defined resources in part 4 of ISO 16972.
If you would like to know how the structure of a valid CxF3 file as well as a user-defined CxF/X‑4 resource should look like, you can find examples at https://standards.iso.org/iso/17972/-4/ed-2/en/.

Can I measure my test charts with a third party application?

Yes, but the third-party software needs not only the test charts themselves, but also additional information about the exact chart layout. You can export both in GMG OpenColor: the test charts as PDF files, the metadata as CGATS files. These formats can be read by all common third-party applications.

Please export the test charts themselves first, and then the corresponding metadata.

  1. In GMG OpenColor, open the tab Database.
  2. From the menu on the left, choose Test Charts.
  3. Double-click on the test chart that you want to measure with the third-party application.
    A new window opens.
  4. Click on the arrow to the left of Finalize to open this section.
    The view with the single test chart pages opens.

  5. Please follow steps below for every single test chart page:

    1. To the right of the test chart page, click on the Export icon .
      A dialog opens.
    2. Under File Name, enter a name for your test chart page.
    3. As File Type, choose PDF files (*.pdf).
    4. Confirm by clicking Save.
  1. In GMG OpenColor, open the tab Database.
  2. From the menu on the left, choose Test Charts.
  3. Double-click on the test chart that you want to measure with the third-party application.
    A new window opens.
  4. Click on the arrow to the left of Finalize to open this section.
    The view with the single test chart pages opens.

  5. Please follow steps below for every single test chart page:

    1. To the right of the test chart page, click on the Export icon .
      A dialog opens.
    2. Under File Name, enter a name for your test chart page.
    3. As File Type, choose CGATS measurement templates (*.txt).
    4. Confirm by clicking Save.

How can I use my Epson SureColor SC-S80600 with GMG solutions?

We have created a guideline for you which guides you through the most important steps and functions when using your Epson SureColor SC-S80600 with our solutions. You can find this and further documentation on our GMG ColorProof tutorial page under the following link: GMG ColorProof Tutorials

Converting

What are separation rules?

In simple terms, separation rules are a kind of translation tool for colors. If your input file contains a different color space than your output system, the colors need to be converted to the color set of your printer. This process is called separation. The conversion values for this color separation are stored in the separation rules and also take specific process parameters into account. This ensures best possible printing results for your custom conditions. Further information on separation rules can be found under the following link: Separation Rules

Can I convert MXN and MXD profiles to MX4?

No, such a conversion is not possible. MXN and MXD profiles are multicolor profiles using spectral data. The MX4 format, on the other hand, only allows the use of up to 4 colors (CMYK) and requires Lab values. However, with a GMG ProfileEditor license, you can create an MX4 profile yourself.

Backup & Restore

Should I create a backup of my installation?

We recommend you to backup regularly, as this will allow your system to be restored in case of emergency. If required, a backup can also be used for migrating your installation to another system.

How do I create a backup?

GMG OpenColor provides an integrated backup function that allows you to manually backup your system if necessary. You can find it under Options (gear icon) > Database > Create Backup.

What To Do in Case of Error Messages?

Error message after update: "You do not have a license to run this application." / "Your application license has expired."

Please make sure that you own a valid license for the installed version. If you have done an upgrade instead of a service update, you need a new license in order to run GMG OpenColor. You can recognize an upgrade by the fact that the number in the first or second position of the version name has changed, e.g. from version 1.1.x to 2.0.x or from version 2.3.x to 2.4.x.

In this case, the error is caused by the Application Service not being updated. Please uninstall the Application Service from the list of installed applications, then reinstall it.

  1. On the left side of your Windows taskbar, click the Start button and choose Settings > Apps & Features.
  2. Depending on which version of GMG OpenColor you have installed, you will now find either AppServiceV1 or AppServiceV2 in the app list.
  3. Select the appropriate AppService and click Uninstall.
  4. In your file manager, open the GMG OpenColor directory.
  5. In the GMG OpenColor directory, enter AppService into the search bar and you will either see the file AppServiceV1.msi or AppServiceV2.msi.
  6. Double-click the file and the Application Service will be re-installed.

Error message: "Connection to the dongle cannot be established. Please plug-in the dongle."

If no connection can be established to your dongle, this can be due to the hardware as well as the software.

  1. Is the LED on your dongle lit?

    If no, your dongle is defective and needs to be replaced. Please contact us.

  2. Does your dongle work on another USB port?

    The USB port you used before is defective and needs to be repaired or replaced.

    Please make sure that the latest dongle driver version is installed. You can download it as CBU Setup from the manufacturer's website.

    If your dongle is not recognized despite having the latest driver, it may be defective and needs to be replaced. Please contact us.

  3. Has the dongle only stopped working after the last update?

    If yes, it seems that the License Application Service was not updated. Please uninstall it from the list of installed applications and re-install it.

    1. On the left side of your Windows taskbar, click the Start button and choose Settings > Apps & Features.
    2. Depending on which version of GMG OpenColor you have installed, you will now find either AppServiceV1 or AppServiceV2 in the app list.
    3. Select the appropriate AppService and click Uninstall.
    4. In your file manager, open the GMG OpenColor directory.
    5. In the GMG OpenColor directory, enter AppService into the search bar and you will either see the file AppServiceV1.msi or AppServiceV2.msi.
    6. Double-click the file and the Application Service will be re-installed.

Error message: "Not implemented – Label to chain / Mxc color error."

If you receive this error message when trying to print dynamically, there is a corrupt file within the GMG OpenColor project. Please perform a database cleanup after backing up your system first.

Error message: "Error updating database."

If you receive this error message when starting GMG OpenColor, there are two corrupt files in your database folder and must be deleted.
  1. Open your file manager.
  2. Browse to the GMG OpenColor database folder by entering %programdata%\GMG\GMGopenColor\DatabaseV2 into the address bar and confirming with Enter.
  3. Delete the file _document.
  4. Delete the file sub_object_files.

    5. Now GMG OpenColor should launch successfully.

How can I clean the database, e.g. in case of an error?

In GMG OpenColor, there is an automatic function for cleaning up the database. You can find it under Options (gear icon) > Database > Cleanup Database
  1. Open GMG OpenColor.
  2. On the top right, select Options (gear icon) > Database > Cleanup Database.
    A pop-up opens.
  3. Set the check mark at Create Backup before Cleanup.
  4. Confirm by clicking OK.
    GMG OpenColor is closed automatically.
  5. Relaunch GMG OpenColor manually.
  6. GMG OpenColor starts the backup and cleans up the database. This process may take a few minutes. You can follow the progress via a progress bar.

    7. Do not close the window until the process is complete.