# Transform colors. Help please

**URL:** https://forum.kirupa.com/t/transform-colors-help-please/121491
**Category:** Uncategorized
**Created:** [September 3, 2004, 7:44am UTC](https://forum.kirupa.com/t/transform-colors-help-please/121491 "2004-09-03T07:44:58Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![mx\_guest2004](https://avatars.discourse-cdn.com/v4/letter/m/e47c2d/32.png) [@mx\_guest2004](https://forum.kirupa.com/u/mx_guest2004)
#### Post date: [September 3, 2004, 7:44am UTC](https://forum.kirupa.com/t/transform-colors-help-please/121491/1 "2004-09-03T07:44:58Z")

</div>

Hi,  
Does anybody here know how to calculate different parameters :  
ra, rb, ga,gb, ba, bb, aa,ab when transforming from one color to another ?  
Example: I want to change from #FFFF00 to #993300  
according to photoshop the RGB for #993300 is R=153, G=51 and B=0  
What is the right method to calculate these parameters?

Thanks 🙂  
mx-guest2004