You need an embossing powder to match a particular color of ink? Place clear UTEE in mixing (disposable) container. Add several drops of alcohol inks. Mix with a craft stick until alcohol evaporates and mixture is smooth.
Okay, Tim Holtz demonstrated this but if I'm not mistaken, Suze Weinberg has done something similar when using her melting pot. She melted clear UTEE then put drops of ink into the liquid UTEE, swirled them together to marbleize then dipped small cardboard squares, face down, into the mix.
Suze used Colors To Dye For inks (a dye based, heat safe ink). The colors can be blended for custom colors, too. I've looked at both Suze's website and Ranger Industries and see nothing listed as Colors To Dye For...only dye based inks.
Here's the link to the show where she makes the marbleized things.
http://www.hgtv.com/hgtv/crafting/article/0,,HGTV_3352_2248447,00.html