A blue/purple comb indicates a lack of oxygen in the blood stream, which points to heart failure or respiratory disease.
Eyes: Should be bright and alert with no discharge. If both eyes are affected with discharge then this can point to mycoplasma. If discharge is only present in one eye then there may be damage to it, which has caused an ulcer. This may need antibiotic drops form your vets.
Beak: Beaks that are overgrown or twisted may need regular clipping and can cause difficulty eating.
Nostrils: Check for discharge and/or sneezing. This could point to an upper respiratory infections.