I tend to stick with white candles for most of my spellwork and even rituals. Colors, however, can often provide an added ‘kick’ to the mood, and symbolize various meanings to you.
To make directional or ‘quarter’ candles, to represent earth, air, fire, and water, I suggest using a mix of modge podge (or thinned glue) with food coloring. You then paint any glass holder, or even the metal part of a tealight candle. I even add a bit of Mica powder to add sheen.
Before (I bought these at the dollar store);
After painting them with the glue, food color, and Mica powder mix;
You can’t really see the sheen on them, but Mica powders add a bit of metallic hue to the mixture. I got some for card making, and used a coupon at Michael’s. The colors come in copper, gold, and even a lovely pearl color.
Its an easy method to color-code your candle holders or any glass item.