Here are a few measurements using a Spyder, HCFR Colorimeter, and Voodoo Screen Test Patterns:
All measurements were taken with the screen set to a maximum brightness of 125 cd/m2.
Measuring on a perfect screen would result in a straight line at 2.2 (higher number=darker, lower number=brighter).
Gamma is broken on Voodoo Color - you'll either get overemphasized colors with dark mid-tones and correct low-tones or bright low-tones and correct mid to high tones (everything will looked washed out).
Gamma is more consistant on the default kernel, but no where near optimal.
The fix would be to be able to adjust the gamma for only the low-tones (0% gray to ~15% gray).
The default the color temperature is way off.
Color temperature is quite good after calibrating - almost 6500k across the board and this could probably be optimized some more with the current adjustments.
Compared to the sRGB colorspace (the default on Android) the Epic's color space is too large - resulting in a somewhat gaudy/oversaturated image.
The ability to adjust saturation for each color could fix this.
Measured Voodoo Color settings:
To test - set your Voodoo Control settings to what I am currently at and go here on your phone:
Or even better download the image, open with quickpic and zoom to 100% (make sure you have Force Decode True Color enabled in Settings>View).
The first and second square should be just barely visible, and each after should get slightly brighter.
On my phone square 2-13 are pretty much the same brightness, then each after changes slightly (although not as much as it should). This can be partly fixed if one would lower the Gamma Offset, but then the brighter greys will be too dark - thus producing a strange flat look to certain tones and losing detail.
I wonder what would be involved in fixing these issues (the gamma to start), or maybe it is just my screen.
Also - I am on Nyan 4.1 and AOKP b31.