I've colored lots of cherry with lye.

You can buy lye at most groceries or hardware stores.

First of all: Wear eye protection! you don't want to get any on you ---
especially the eyes

Second, wear neoprene gloves.

Mix a weak lye solution. Maybe 2t per quart at most. CAUTION --- Use COLD
water. Dissolving lye will generate heat. and could bubble up with warm water.

Swab on the solution and let it sit until you get the color you want. Then
rinse thoroughly first with cold water and then swab on some vinegar to
neutralize any remaining lye. Rinse that and dry with a clean cloth.

I usually use a heat gun to evaporate the remaining water in the wood. This
process may raise the grain slightly which you can smooth down with a fine grit
abrasive or Scotch Brite pad.

Then finish however you want --- linseed oil, tung oil, paste wax, Watco,
Briwax, varnish, Danish oil .... It all looks good.

I don't know how lye affect maple. I'd suggest testing on a piece of scrap.

Joel