I beg the difference with the colored zupreem pellets!!!! I first started using them over 16 years ago and I have been happy with them. When I take my birds in, they all get good results, they eat zupreem "colored" pellets. I have tried the natural color stuff and my birds wouldn't even acknowledge them. BUT during anytime when a bird have a low weight level, by feeding pellets does NOT help with weight gain!!!! You must supplement with high protein diets to help with weight gain. I dealt with that in the past after the virus break out. That's when I started the high protein formula I make at home to feed. And I added more seeds to their diet for the time being.
When it comes to pellets I am a critic. At first I fed Rosie a mixture of lafeaber's, zupreem natural, and Roudybush. When I changed her to Harrison's it made a visible difference in her health and she started gaining weight much faster. My vet explained why those other brands are not as good for birds and I trust her. I get Rosie and Kenji's pellets shipped to me and don't mind the slight inconvience. I want to feed them the best that's out there, and the best fresh foods.
I agree that some pellets are better than others and some species benefit more from a specific one. For example, my Grey gets the Harrison's High Potency. The most important is that SHE LIKES THEM AND EAT THEM. My Conures won't touch the Natural Zupreem but will eat the Fruitblend. Zupreem is a good company with good pellets, if they are eating the Fruitblend, it is way healthier than not eating pellets at all.
I mean, I eat Ezekiel bread mostly (made with sprouted grains no flour), it is VERY good for you.....however Ezekiel also make the low sodium kind. Less salt the better right? But hey it's not as good testing to me so I tend to eat less of it and supplement with other food instead. So I get the regular kind now.
Same for birds. Eating quality pellets is already a very healthy food for your parrots! How much healthier you gotta be!!! If they don't eat it, it's a waste for you and an unhealthy diet for your bird.