Lighten each logo path color instead of white
## What does this MR do?
Changes highlight/loading colors of tanuki from white to a lighter version of each path color
## Why was this MR needed?
Since the logo is no longer on the dark sidebar, the highlight color was getting lost against the light gray background
## What are the relevant issue numbers?
Closes #18521
## Screenshots (if relevant)
cc @jschatz1 @lbennett @dzaporozhets
See merge request !4690
