Stain will not work over a preapplied finish and it will not change an existing color. You would need to remove all the finish and the yellow color---applying blue stain over a yellow door would result in a greenish blue.

The color of applied stain is different on each different type of wood as well, meaning even when applied to a new unfinished door, the color will only be close to the sample color.

I understand that. We are having professional painters come do our basement, and they are going to strip the door and stain it for us while they are here. The finish is coming off and it is just time to redo it to it to preserve the door. I guess I can get a piece of alder and try a sample of the stains I like and see how they take. I was just wondering if anyone had any experience with it these unusual colors.

I use several primary color wood dyes on maple when making one off back scratchers/oven rack pulls.

Alder is similar in color, but softer grain. Stains often do not penetrate the wood as deeply as dyes.

That is helpful thank you. The blue I want is less vibrant than the colors you use. We really have to be able to still see the grain and characteristics of the wood.

Like I wrote---that wood is maple---there is little grain pattern. That dye does not obscure the wood as much as a stain would.

That blue is much more bright and blue when put on white paper. The wood cuts the color.