How to reproduce:
1. Create new project file
2. Import Conifer tree assets
3. Create Terrain
4. Select "Place Trees" in Inspector Window
5. Add "Conifer_Desktop" tree (notice, that Random Tree Rotation appears, Color Variation no)
6. Add another tree, expand "Conifer_Desktop" and add "Conifer_Desktop_LOD0" (Notice, that Random Tree Rotation has gone, Color Variation appears)

Expected result: There should be both "Random Tree Rotation" and "Color Variation" in Tree settings
Actual result: "Random Tree Rotation" and "Color Variation" depends on each other

Reproduced with: 5.5.4f1, 5.6.3p2, 2017.1.0f3, 2017.1.1f1, 2017.2.0b10, 2017.3.0a7