How to get rid of blueish outline on renders V-ray Next

eithe1

Hello everyone,
how can i rid off blueish outline on render. I've aplied alpha channel as a mask to render output in PS and got this result - trees are 3d objects.

Software:
sketchup 2019 + v-ray next

Problem

cotty

Maybe the alpha map isn't agressive enough the prevent the blue sky (?) shining through?

eithe1

OK, i've got solution On Environment Tab, i've repliced Background map which was /sunlight to color black, and turned on GI replacement and set there /sunlight.

Edit:dont forget to also edit reflection replacemet same as GI