Richard Oedel replies: I stock only raw and burnt umber, raw and burnt sienna, as well as ocher, titanium white and ivory black as oil paints. A small tube of each will last you a long, long time. I use it only for touch ups, with the smallest brushes you can buy at the art store.
I can’t talk about the powders, but the TransTint liquids are useful for many things. My colleagues in the shop use them often as the full stain treatment for a particular job, but I usually only use them to modify a color I already have. Red Bordeaux, brown mahogany, green (to cut something that is already too red), black and honey amber are the ones I go to most frequently. But most of all I use either Behlen (the retail version of Mohawk Finishing product) NGR stains or just straight Minwax stains, mixed together to create what I am looking for. They are not great stains, but the colors are ok, and when mixed with Retarder have more of an open time and give you fewer problems with a dry edge. I frequently mix them and then add a drop or two of TransTint to adjust the color.