To avoid dull looking hair, use a shampoo with an acidic pH, which will seal the hair's cuticle, hence boost shine.

Detangling hairbrush
Travel brush - Christophe Robin
Cleansing mask with lemon
Regenerating shampoo with prickly pear oil
Regenerating mask with rare prickly pear seed oil
Damaged Hair oil
color protection shampoo
color protection
color protection for blonde hair