Make your own, do it yourself embossing ink ;)
It's pretty cheap and pretty easy...
Any color that you like of Powdered Clothes Dye (Rit for example)
1/4 Teaspoon of Alcohol
5 Tablespoons Glycerin
Be careful and blend alcohol & dye till it is the same consistency of a thin cream. Start with 1/2 tsp of dye and then continue adding only 1/8 teaspoon at a time till is the same consistency of a thin cream.
Then you can add glycerin. Make sure you blend well. After that, pour (homemade or storebought) ink over your stamp pad or you can use a fine foam rubber pad. Spread the ink evenly with a brush, popsicle stick, etc.
Some more ideas....