Is there a dye that can be applied to a small white scar left on my cheek after an injury?

You should see a cosmetic dermatologist who specializes in scars.  this typically would need a revision but injections with 5fu/steroids may be able to help without surgery. Scars can be improved but "cure" would have to be evaluated in person.  Best, Dr. Emer.

Our treatments use combination therapy to improve the epidermis and dermis for most deep scars. The options available for acne scars depend on the character of your scars, in terms of topography and contour. We see atrophic and hypertrophic acne scars, as well as scars that have hypo and...

This is likely pigmentation and would need resurfacing or pigmented laser treatment, please speak to a well trained laser physician.  Best, Dr. Emer.

If this is a cyst it can be surgically removed and then cosmetically improved with lasers and microneedling.  Best, Dr. Emer.

I suggest getting this treated for the infection and "decolonization" of your body and then doing laser treatments to improve the final results.  Silicone gel and topical antibiotic should be employed now.  Best, Dr. Emer.