Just from experience, the best tint I've seen for dope is House of Kolor's Kandy Koncentrates. Pretty much any color you want, don't fade in the sun and is a killer look. My buddy Pete Peterson did an article in Stunt News about this recently. Weirdly, he uses Lime Gold to tint butyrate and it comes out a nice yellow over balsa. What's underneath makes a big difference in the color of tint you choose.