For a small fee, allow users to order a replacement physical card in a new colour. For example, if your card is lost/stolen/compromised, you can choose to get a free replacement in the same colour as your existing card, just like now. Or, if your card is lost/stolen/compromised you can pay a small fee ($10 or less) to pick a new colour for your replacement physical card. Perhaps this option is also made available when your card is due to expire soon; pay a small fee for your new card to be a new colour.