# Color problems accessing Slicer3D on an Ubuntu install

**URL:** <https://discourse.slicer.org/t/color-problems-accessing-slicer3d-on-an-ubuntu-install/1282>\
**Category:** Support\
**Created:** [October 25, 2017, 1:13am UTC](https://discourse.slicer.org/t/color-problems-accessing-slicer3d-on-an-ubuntu-install/1282 "2017-10-25T01:13:53Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![dcantor](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/dcantor/32/782_2.png) [@dcantor](https://discourse.slicer.org/u/dcantor)\
**Post date:** [October 25, 2017, 1:13am UTC](https://discourse.slicer.org/t/color-problems-accessing-slicer3d-on-an-ubuntu-install/1282/1 "2017-10-25T01:13:53Z")

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Problem report for Slicer 4.8.0 linux-amd64: [please describe expected and actual behavior]

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/c/c/cce0cc6a80568c94d57b31b889ddbb7522be0b83.jpeg)

the image shows the colors are completely off. I am using Slicer3D through a VNC connection. Slicer3D is hosted on a Ubuntu machine.

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**Author:** ![ihnorton](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ihnorton/32/9_2.png) [@ihnorton](https://discourse.slicer.org/u/ihnorton)\
**Post date:** [October 25, 2017, 1:29am UTC](https://discourse.slicer.org/t/color-problems-accessing-slicer3d-on-an-ubuntu-install/1282/2 "2017-10-25T01:29:43Z")

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Did older versions of Slicer work ok? The gradients look kind of like compression artifact if VNC downgrades the quality due to insufficient bandwidth. Others might have suggestions, but this is may not be a Slicer problem per se.

Other people have used VNC successfully – see thread below. I’ve also used TeamViewer a few times and had good results, although usually with a Windows system hosting Slicer.

> [@Saving images from slicer views in headless compute node](https://discourse.slicer.org/t/saving-images-from-slicer-views-in-headless-compute-node/138/9):
>
> (Edited the previous post to use display :11 rather than :1 to match Mike’s use case)

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [October 25, 2017, 1:50am UTC](https://discourse.slicer.org/t/color-problems-accessing-slicer3d-on-an-ubuntu-install/1282/3 "2017-10-25T01:50:38Z")

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Looks like color quantization artifact to me, too. These instructions may help for setting up VNC appropriately: [https://askubuntu.com/questions/281177/colours-background-messed-up-in-vnc-viewer](https://askubuntu.com/questions/281177/colours-background-messed-up-in-vnc-viewer)

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**Author:** ![dcantor](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/dcantor/32/782_2.png) [@dcantor](https://discourse.slicer.org/u/dcantor)\
**Post date:** [October 25, 2017, 2:00am UTC](https://discourse.slicer.org/t/color-problems-accessing-slicer3d-on-an-ubuntu-install/1282/4 "2017-10-25T02:00:03Z")

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I will try an older version. No VNC compression used as I configured it for maximum quality.

Thanks.

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**Author:** ![dcantor](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/dcantor/32/782_2.png) [@dcantor](https://discourse.slicer.org/u/dcantor)\
**Post date:** [October 25, 2017, 2:14am UTC](https://discourse.slicer.org/t/color-problems-accessing-slicer3d-on-an-ubuntu-install/1282/5 "2017-10-25T02:14:44Z")

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I don’t think it is a quantization problem. The problem happens inside Slicer. Other than that the desktop looks totally fine. And inside Slicer it seems like the lookup tables are all wrong. Also I had already configured VNC for maximum quality… check this side to side between chrome and slicer. The background in Slicer looks off and as shown in my previous post the DICOM volume looks off too.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/d/d/ddaf037c16e53443653e5657027d508577138d56.jpeg)

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [October 25, 2017, 2:46am UTC](https://discourse.slicer.org/t/color-problems-accessing-slicer3d-on-an-ubuntu-install/1282/6 "2017-10-25T02:46:53Z")

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It seems that only the OpenGL windows colors are off. Can you check other applications with OpenGL windows? Can you try with other VNC clients/servers and other remote desktop software (TeamViewer, etc)?

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**Author:** ![dcantor](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/dcantor/32/782_2.png) [@dcantor](https://discourse.slicer.org/u/dcantor)\
**Post date:** [October 25, 2017, 4:46am UTC](https://discourse.slicer.org/t/color-problems-accessing-slicer3d-on-an-ubuntu-install/1282/7 "2017-10-25T04:46:07Z")

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Update:

TeamViewer did not install (problem with AWS).

Tried with Slicer 4.4 and had the same problem

Tried with Slicer 4.0 and it did not start because a Qt dependency.

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**Author:** ![ihnorton](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ihnorton/32/9_2.png) [@ihnorton](https://discourse.slicer.org/u/ihnorton)\
**Post date:** [October 25, 2017, 10:39am UTC](https://discourse.slicer.org/t/color-problems-accessing-slicer3d-on-an-ubuntu-install/1282/8 "2017-10-25T10:39:22Z")

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Try something that is pure OpenGL (no VTK) like [MeshLab](http://www.meshlab.net/). It is small and should be in the package repository already.