Super Bright! (Help)

[GraphicsKid]

Diffuse IS the light.

Diffuse color (and in the case of Amnesia, the intensity as well) is the color the light is. The scroll bars in the color chooser only go up to 1, but you can type in any number you want.

The last value, alpha, controls the amount of specularity the light gives off. Specularity is a fake reflection of the light, like a white spot bouncing off the ground. If it's not a "real" light source in the scene, then you should set it to 0, otherwise the reflection will show up in game and it'll look weird to have a non-existent light source reflected.