The WikiSpecies logo has some gradients that should be removed and replaced with the actual green-blue-red colour palette to be consistent with the other flat logos already created, such as Incubator, Commmons, Meta, etc.
The Wikiversity logo should have the current blue of the official colour palette, #006499.
The MediaWiki logo should be flatted for reasons up above, and also use a flat yellow colour (looks like an official one hasn't been decided yet). The brackets should also be the #006499 blue.