my O's poo has always sunk, even almost defiantly so against the weak draw of 45 ft of Python suction.
I feed almost strictly on pellets. I leave the other stuff as more rare treats. The pellets has a well-balanced range of protein, fiber, fat, vitamins, and minerals to keep them healthy without ever tasting flesh in non-pellet form in their lives.
I use treats to get what I want. Happiness after water changes. Brighten the mood when a bit sulky/lazy. The less I feed treats, them more readily pellets are eaten (and the better eaten/less expelled).
I look at it this way, if I eat one of my favorite treats, white chocolate, every day ... it doesn't seem as special or indulgent as it does if it is once a week or month.
My O's poo is of various colors ... but it is directly related to the food. Sometimes shrimp can make it lighter, sometimes red it seems, otherwise, it is pretty consistent.
Just like if you had some food coloring or colored drink/candy in excess
Just watch for things like an empty casing like look.
My O's poop is getting quite big as he gets older ...