Color of texsky

how to control the appearance of color and gradient in texsky GI & BG ?

The sky texture in vray isn’t based on a bitmap, so you can’t control color and gradient directly, as far as i know.
What you can do is adjusting the appearance by altering the parameters.
Here is an overview:
http://docs.chaosgroup.com/display/VR2R/VRaySun+and+VRaySky

Additionally, you can render your picture with an alpha-channel an adjust (or even change) the background in photoshop.

Thank you very much, deis