Blender's color picker and gamma.

Support Lighting and Rendering
1

When I render a shadeless material with the color: R-0.5, G-0, B-0, And I click on the image in the Image editor, the information below tells me it is the same color as intended.

But when I open the same image in GIMP/Photoshop, the color comes out to be R-188, G-0, B-0.
When I open the saved image in blender’s image editor again, even blender gives the color as R-0.73, G-0, B-0. (I assume its the same as R-188 since 189/256 is pretty much the same)

I don’t think it’s a coincidence that 0.5^(1/2.2)=0.73, 2.2 being the system gamma for a Windows system.

So the question is , why is this happening and how the heck do I get the color I want.
This happened as I was learning about gamma and linear workflow, so I have a few more questions:

  1. Is the problem with blender’s color picker window or the color sampler, or both?

  2. Does the “gamma”, which I believe is stored in an image, alter the actual image data or is it just a no. stored along with it.

  3. Does the color picker use a linear scale at all (R-128 = R-0.5, right?)

2

I can’t vouch for the maths, but Blender now does all its calculations in Linear Colour space, so the colour picker is gamma corrected. Gimp works with rgb, so it is not. Image textures in Blender are rgb.

Basically, you don’t have a problem.

3

Btw, the hex field in the color picker is RGB, so if you have a specific color you want, enter the hex code here, Blender will convert it for you.