I think some of these are clearly better replacements than others.
We can't expect them all to look like higher-poly versions of the old colours, but I think they could at least be in the same colour range. A few are not.
For me, the worst replacements are:
- the white windserpent. The replacement is in no way white, nor was it ever intended to be white. It was created to look like a sidewinder snake. The black one should also have a lot more blue in its body, but it's still not as bad a replacement as the white one.
- all the thunder lizards I think are terrible replacements for the old ones, even though the model is lovely. The green with red spikes is perhaps the closest to the one it replaces, but the spikes still look so poor in comparison to the originals. The grey-green being replaced by the brown is a truly unfathomable choice.
- bonespider(2)_ochre: the two colours aren't even in the same spectrum range.
- minespider2_olive: again, it completely missed the palette. most of the mine spiders are pretty good, though.
- minespider2_cave - completely different end of the light/dark spectrum to the original
- the hyenas lack texture, and look more like they were dipped in paint. The red seems to me to be the worst of them, though the purple isn't good either. The 'black' looks like someone just read the name on the original skin and never looked at the skin to see what it actually looked like (it actually should be dark brown). It's strange that the replacement creature that
shouldn't have high saturation does, while the replacement creatures that should (crabs, spiders, etc.) lack it.
- same with gorilla_grey: the original 'grey' was actually more like white, but I wonder if the artist didn't check that and just went off the name.
-
the truesilver crab lacks any kind of shine at all, but it should be brightly metallic. The lack of shine is obvious in the new crabs in general (in fact all the new arthropods, which should have much higher contrast to give the impression of smooth, shiny shells). Maybe (hopefully) something will be done to the model to address this, like an over-effect. It could conceivably already be there but the model viewer isn't showing it. - update: the shine is added on the model.
- the white vulture mostly has the same colour palette, but it's extremely dull compared to the original. and no red eyes

My favourites:
- most of the mine spiders, just not the ones that are meant to be bright and shiny
- the red gorilla, and mechanical gorilla are gorgeous
- some of the crabs are lovely replacements
- the robot chicken is spot on and beautiful
- the tarantulas are gorgeous!
Most of the model work seems really lovely. And the art is all perfectly good for new creatures, but it's just for replacement beasts that I think some of it needs work.
Key sentence for me: things that should be subdued and finely-textured (e.g. hyenas) are instead often over-saturated, while things should be bright, saturated or high-contrast (spiders, reptiles, crabs, some birds) are often instead dulled or subdued.