Filtered pressured oxygen 80 miilion years ago
What filter?  Modern vertebrate blood is always red (with just one exception AFAIK: https://en.wikipedia.org/wiki/Channichthyidae ) because it is based on hemoglobin.  Given that birds, which descend from one branch of the dinosaurs, have red blood, it's likely that the dinosaurs did as well.  Likewise plants are mostly green due to the chlorophyll used for photosynthesis, another thing that would be strongly conserved by evolution.