There is no healthy way. Whitening/bleaching do not change the shape of your teeth but alas, dentine doe not bleach well, if at all (it just gets more sensitive to temperature change). Veneers done well will have a 'good' shape to ensure gum health. As for trying to find something to paint on, let's explore that if you place a opaque white dental liquid filling but it being so thin, will eventually wear off real fast with everyday brushing. Sorry, no miracle solution.

eg https://www.tokuyama-us.com/estelite-color-dental-restorations/