Grout is very porous, and will stain fairly easily. Anything that can stain can be recolored.
Getting the color deep enough or getting the shade right will be very difficult, but it could be done. Stop by a paint store or a home center & find someone with enough gray hair to know how to match colors without the computer & ask them.
Try whatever remedy you come up with under the fridge or stove & make sure you like what you get.
As for damaging the tile, ceramic & porcelain are basically glass & you can get very aggressive with removing any oops or boo boo's. This will turn into a job you will wish you had never started but you did ask.
Another possibility is to have an installer regrout for you. Lots more money but more permanent results.
if you mean without tanning or false tanning, there is no other way to darken your skin
NO
cuz u grow
Yes, if you try to darken your hair, the highlights will darken as well, but will appear lighter than the rest of the hair.
See your Doctor
try Black Henna powder; available from health food shops.
To darken wood stain without stripping it, you can apply additional coats of a darker stain on top of the existing stain. This will deepen the color without removing the original stain. Make sure to test the new stain on a small, inconspicuous area first to ensure it achieves the desired shade.
One way to darken finished wood without sanding it is to apply a wood stain or wood dye directly onto the surface. Make sure to clean and prepare the wood before applying the stain or dye to ensure even coverage and a desired color.
To darken blue paint without using black, you can mix in a small amount of a darker shade of blue or a complementary color like burnt umber or raw sienna. Experiment with different ratios until you achieve the desired shade of dark blue.
Some glaucoma medicines will darken the iris color.
The noun forms for the verb to darken are darkener and the gerund, darkening.
You can darken your hair using the Black Ice spray, or the natural remedies such as herbs sage and rosemary.