Fix color selector conversions in OCIO+Internal mode
The pipeline of he color is the following:
- Convert the color to a RGBA-32-bit color space supported by OCIO. Unially, this color space coincides with the one use by the image.
- OCIO applies Exposure and Gamma correction
- If color management mode is not internal, OCIO converts the color space for the output device, otherwise the color is converted by the display converter explicitly.
- Display converted converts the resulting data either in qt-widget color space or to the opengl-surface space.
The problem of Internal mode happened because steps 2 and 3 were
swapped, when in Internal mode. Now everything is applied in a correct
order.