Texture based light emission?

[neo0.]

I saw this in the bugs section of the forum

in that case it has a base emission which can be constant or be modulated by a texture or evaluated by a shader

And im wondering how would we set up a texture, so it emits a different color of light, based on that of each pixel in the texture? If this is indeed currently, possible, it would be nice to have some photo shop style artistic functions for the texture, like change the lighting to a red hue (where all the light emitted is different shades of red.)

[Kram1032]

textured emitters?