To reproduce:

1. Create a Sprite game object
2. Try changing its color (see that RGBA values are in range (0 - 255))
3. Try animating the color in Animation window by changing individual values of a keyframe
4. Observe that RGBA values are in range (0 - 1)

Expected: show the rgba values in the Animation window in range of 0 - 255 or have the animation window support color pickers, allowing artists to simply store colors in the picker palette and reselect them for consistency

Reproduced in 2017.1.4p2, 2017.2.3p2, 2017.3.2f1, 2017.4.7f1, 2018.1.8f1, 2018.2.0b11, 2018.1.8f1, 2018.2.0f1, 2018.3.0a4