Soap bubble material issue

I have Created Soap bubbles and given material, my animation is collecting all bubbles to a particular point.
When its come together, material renders black, instead of soap bubble colour.
Let me know the reasonuntitled

If you are in Cycles, make sure that in the Properties panel > Render > Light Paths, you have enough Transparency

THank you
Transparency I changed 25, so looks better now. but still, 10% blackness is there, but I am ok