To reproduce:
1) Create a new project and create a new scene
2) Go to Edit->Project Settings->Player and in 'Other settings' in inspector tab set 'Color space' to 'Linear'
3) Create directional light game object
4) Click the color picker for the directional light
5) Set the color to rgb (64,128,192)
6) Notice that colors are not the same in 1 and 2 areas (check screenshot that I have attached) and in color picker(?)

It works as expected in Gamma color space.

The issue is fixed in Unity 4.3.7 Patch 1 version.