Hydrogen peroxide is the cheapest stain remover for laundry I have ever found. Especially on those mystery stains that appear & reappear after washing or storing. I have removed set in stains that include baby formula, ketchup, mustard etc~you know those really tough stains. I haven’t ruined a piece of clothing yet. (You hear that? knock, knock that’s me knocking on wood) I use it on all colors, too. I simply put a small amount in the cap dip, a toothbrush in it and blot it on the stain. I leave it until dried. Repeat the process until the stain disappears & launder clothes as usual. If you are reluctant about using it on colors, find an inside seam that will be unnoticeable and test a drop or two. If no color is removed after it dries, you are good to go.
Also, use it full strength on white sinks to remove stains. Splash a little on and let it sit.