Feathers are a strong indicator of health, so the most vibrant feathers are seen when a budgie is happy, healthy, and receiving a balanced diet with adequate vitamins/minerals. Additionally, the colors can change a little bit after the first moult for some mutations; yellow faces tend to get brighter, etc.
just waiting for Zazu and Saphire to moult, the shop we got them from cliped their wings, which i find sad because they want to fly but can‘t. Blue and Kiwi are always head bobbing and being talkative.[/QUOTE]Good nutrition for your budgies is key to keeping them healthy, happy and their feathers vibrant.
Star has offered you excellent information.
It's great that your budgies color seems more vibrant at this time.
Feathers - A Window into your Budgie's Health