System Information
Win8.1 64bit GTX980
Win7 64bit GTX560ti

Blender Version
Broken: 2.73a

Short description of error

• When a brush without texture, the color painted is the same as picked.
• When a brush with texture, the color painted often turned out brighter than picked.

colors are in pairs
Left: with texture; right: without texture
See the color palette for colors picked from the result.

Note: hue, saturation and value shift at random.

Checked color space, but not related.

Exact steps for others to reproduce the error

1. pick a color
2. paint with texture
3. paint without texture
4. pick the color painted, with and without texture.