The original concrete dyes were all very small particles of color dissolved in an acetone base. When sprayed they dry very quickly (15-30 seconds). You can spray then lightly and seal with a no solvent or water borne sealer or as is often done with polished concrete, they are sprayed heavily then the extra residue is washed off before sealing. The look is a lot like you would expect from an ink stain. They bare interior stains because they are not UV stable and the color will fade if used outdoors.

The newer exterior water and acetone based dyes are more like paint pigments without the light and dark bases used in paint (base makes the paint opaque instead of translucent). They are sprayed the way you want the floor to look in the end, no washing off the surfaces. Care has to be taken to not spray them too thick as they will begin to look like a painted surface. They have a little acrylic in the mix so you can use a very low solvent sealer, 100% sealer or a water borne one. These are UV stable and can be used outside.