Veltharis ap Rylix
Legend
Mostly comes down to the color scheme - blue, but complemented with a yellow/tan/brown underside that looks like it would help camouflage it when flying amidst dust clouds and sand storms, plus a horn that could easily pass for a jagged rock sticking out of the ground or the side of a dune while the rest of the dragon was burrowed just beneath, waiting to pounce.How did the 3e design feel like a desert dweller to you?
By contrast, the new blue's color scheme is all blue and shades of gray, which seem specialized for hiding among clouds, particularly thunderclouds, and its horn is a smooth spike.