're-tinted' is formed from the prefix 're-' (from Latin 're-' meaning 'again') combined with 'tint' (from Old French 'teint', from Latin 'tingere' meaning 'to dye').

'tint' came into English via Old French 'teint' (past participle of 'teindre') and Middle English forms; the productive prefix 're-' (Latin) was later attached to form verbs meaning 'do again', producing 're-tint' and its past form 're-tinted'.

Originally 'tint' meant 'to dye' or 'a dyed color'; over time it came to mean a lighter shading or hue, and 're-tinted' now specifically means 'tinted again' or 'given an additional/renewed tint'.