colorLUT and fillAlpha problem

[zhoualibaba]

The color i got is not linear, fillAlphe 0.99/1 changed a lot.I think i got the wrong color.I wonder if it's my fault.
When i use setToolGroupSpecificConfig like this

I got the color like this.
@sedghi The colorLut[1] is transparent. The colorLUT[2]/[3] are completely opaque.FillAlphe has been changed to 1.
The segmentation from left to right use colorIndex 1,2,3.

it seems that colorLUT[1] behave differently。
When i change the colorLUTArray.

The color has changed like this

@sedghi
When i change the colorLut[1] to [77,228,121,255],it seems that colorLUT[1] is transparent.

[sedghi]

Yeah it is a known issue, you can read more here

[zhoualibaba]

@sedghi Thank you for your reply.
So there is no way to have the color act linearly to the opacity.
I want to know why the colorLUT[1] behave differently.

[sedghi]

So no for linear behaviour (as I understand). But colorLUT[1] should not be different than others. I didn't see that in your original post, can you edit your original post and add a bit more explanation?

[zhoualibaba]

@sedghi I have edited my original post .
It seems that the colorLUT[0] affects the colorLUT[1].I try to change the colorLUT[2] from [77, 228, 121, 255] to [77, 228, 121, 0] ,the colorLUT[3] has also changed.

[sedghi]

Do you still see this issue?

[zhoualibaba]

@sedghi Thank you for your reply.
I see that most of this problem has been solved，but the previous color still affects the next color a little.LIke this


When i change the colorLut[2],the colorLut[3] still changed a little.