Urgent Budgie with red discharge

[Fozzy]

Hello, I am hopeing someone can give me suggestions as to what might be wrong with my female budgie. She is about 4 years old. I started noticing these redish discharge marks at the bottom of the cage. I have already taken her to our avian vet and they did some bloodwork and it all came back normal.

 

[Zara]

Hello,

What is her diet?
I recently used some pellets and they made a right mess as the poops were reddish and it stained my birds. I know that some veggies can also stain red.