# Changing Size and color of individual interaction handles of ROI

**URL:** <https://discourse.slicer.org/t/changing-size-and-color-of-individual-interaction-handles-of-roi/26360>\
**Category:** Development\
**Created:** [November 21, 2022, 8:30pm UTC](https://discourse.slicer.org/t/changing-size-and-color-of-individual-interaction-handles-of-roi/26360 "2022-11-21T20:30:40Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [November 24, 2022, 12:02pm UTC](https://discourse.slicer.org/t/changing-size-and-color-of-individual-interaction-handles-of-roi/26360/7 "2022-11-24T12:02:27Z")

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Ah OK, so it’s about ROIs. It is different from what I was investigating. FYI this is what interaction handle means without the special context you just mentioned:

![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/5/b/5bfc91ac3a504a1629dbd0b2b46da35157401c4c.png)

The code is quite similar for ROIs though:

> <https://github.com/Slicer/Slicer/blob/3c592df27e3dccedbd8fcddf05979f59af484f2c/Modules/Loadable/Markups/VTKWidgets/vtkSlicerROIRepresentation3D.cxx#L532-L552>

I think customizing the color could be solved by adding members for the interaction handle colors to the markup display node (initialized with the hard-coded colors), and using these members in the two functions I have linked about colors. Note that in ROIs you have not three but six interaction colors, so this would need to be handled somehow if you want the left-right colors to be different (note the same red color setting for `L` and `R`). Maybe we could have `X`, `Y`, and `Z` interaction handle color getter/setters, with optional `AlternateX` or something similar for the inverse directions in the ROIs. @lassoan what do you think?

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