hi shogun
All stains or (dyes) are not all oil based there are several.
the most common is oil stain of which is actually spirit based and have a binder in it to hold the stain to the wood after the spirit has evaporated.the other most common is water based, but this is normally only used with acrylic finishes. you can put most finishes directly on to an oil stain once well dry, but I always find that a solvent based finish will always enhance the timber grain better.
other stains or dyes include
NGR which are non grain raising and are based on highly volatile solvents, but dry very quickly.
NST which are non strike stains, and usually restricted to commerial production, where speed is essential, but these are only for sraying on and dry in minutes.
others are (matching tints and dyes),(aniline dyes),(vandyke crystals) and the list goes on.
HTH
Dave