Oil dyes are not as commonly used although they are useful in certain applications. They are soluble in turpentine, toluol, lacquer thinners, oils etc., but let dissolve overnight. They are reasonably light fast and penetrate well. Best to seal in color with shellac.
Anilines, synthetic coal-tar derivatives, are relatively inexpensive and easy to use. One "color" provides many hues of that particular color range.
A usual rule of thumb is that 1 oz of dry powder dye will yield from 1 pint to up to 4 quarts of liquid dye, depending on the concentration desired. Never store in metal containers.