# In vtk.js, How to mark the outline with special color in volume drawing

**URL:** https://discourse.vtk.org/t/in-vtk-js-how-to-mark-the-outline-with-special-color-in-volume-drawing/3011
**Category:** Web
**Created:** [April 10, 2020, 1:42am UTC](https://discourse.vtk.org/t/in-vtk-js-how-to-mark-the-outline-with-special-color-in-volume-drawing/3011 "2020-04-10T01:42:31Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![huatianyu](https://discourse.vtk.org/user_avatar/discourse.vtk.org/huatianyu/32/1630_2.png) [@huatianyu](https://discourse.vtk.org/u/huatianyu)
#### Post date: [April 10, 2020, 1:42am UTC](https://discourse.vtk.org/t/in-vtk-js-how-to-mark-the-outline-with-special-color-in-volume-drawing/3011/1 "2020-04-10T01:42:31Z")

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![image](https://discourse.vtk.org/uploads/default/original/2X/6/63ae92cbb6c19bbb3e30179ed124d80d0b56ef54.png)  
The current case is only to modify the grayscale of contour points into inverse color, but the display is still not clear, how to make the contour look clearer?For example, red, do I need to make these points into planes