Gray coloring at child objects?

Question

Canvas

Hello. Could you help me find script for next task. Some times ago, 4 yers I find script which change color all in child objects by grey. But I lost it, and can't find the script again.

Structure:
- Main Gray layer with images script, gray scale script,
- res A
- res Aa
- res Ab
- res B
- res C

No reason how many deep structure was all was gray.
script had slider which can be controlled and create smooth changing.
They work at Unity


Canvas