# The colormap in "Volume Rendering" is wrong when using "fMRI" lookup table in "Volume"

**URL:** <https://discourse.slicer.org/t/the-colormap-in-volume-rendering-is-wrong-when-using-fmri-lookup-table-in-volume/30186>\
**Category:** Support\
**Created:** [June 22, 2023, 6:42pm UTC](https://discourse.slicer.org/t/the-colormap-in-volume-rendering-is-wrong-when-using-fmri-lookup-table-in-volume/30186 "2023-06-22T18:42:56Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![ffr](https://avatars.discourse-cdn.com/v4/letter/f/d07c76/32.png) [@ffr](https://discourse.slicer.org/u/ffr)\
**Post date:** [June 22, 2023, 6:42pm UTC](https://discourse.slicer.org/t/the-colormap-in-volume-rendering-is-wrong-when-using-fmri-lookup-table-in-volume/30186/1 "2023-06-22T18:42:56Z")

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Operating system: Windows 11  
Slicer version: 5.3.0  
Expected behavior: fMRI colormap in “Volume Rendering”  
Actual behavior: Looks like it is using the “Warm2” colormap.

Thank you very much.

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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:** [June 24, 2023, 7:27pm UTC](https://discourse.slicer.org/t/the-colormap-in-volume-rendering-is-wrong-when-using-fmri-lookup-table-in-volume/30186/2 "2023-06-24T19:27:17Z")

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Thanks for reporting, you’ve discovered a problem: colormap is inaccurately copied from color tables that have few entries and sudden changes between them. I’ve pushed a fix that will be integrated into the Slicer Preview Release soon. You can monitor the status of the fix here:

> <https://github.com/Slicer/Slicer/pull/7042>
>
> When a color node with few color table entries (such as fMRI) was used for showi…ng a volume, the "Synchronize with Volumes module" button in volume rendering module very inaccurately copied the color entries to the color transfer function. The problem was that only every 64th color table entry was copied. Fixed the issue by copying up to 24 color entries (evenly sampled in the lookup table) of the table into the transfer function. This number is large enough to accurately represent a color table, but not too high so that users can still edit the color transfer manually.
> 
> Also fixed synchronization of continuous color mapping. All control points of continuous color maps are copied, so these are copied in full fidelity.
> 
> Fixes the problem reported at https://discourse.slicer.org/t/the-colormap-in-volume-rendering-is-wrong-when-using-fmri-lookup-table-in-volume/30186