Please see this post for my contact details :)
https://www.construct.net/en/forum/game-development/job-offers-and-team-requests-28/-paid-and-free-programmer-will-130628
Hi Dop,
I found out the reason for inaccuracy, actually on tap rgba which comes always has 100 as alpha, how to increase that aplha for rgb as fx effect for color/tint has only rgb values to update.
If alpha is fixed then color accuracy issue is also fixed.