In my experience keeping huge schools of assorted Danio and Tetras, I would have to say that Pink Zebra Danio school the tightest of the Danio. Galaxy Rasbora schools loosely, and tends to break off to hide in corners before rejoining the school.
I would recommend Neon Tetras for their color, but their schooling and activity is uninteresting at best when compared to similar fish like the Cardinal Tetra or the Glo-Lite Danio. Don't even get me started on the Glo-Lite Tetra. Those things just suck. They float in place most of the time just readjusting their position in the swarm.
Rummy-noses take the top prize for best schoolers in my opinion, they are highly active, swim quickly, and school tightly. And I don't know where you got your information about their coloring, perhaps you've seen some bad photos or specimens. My rummy-nose are a brilliant white, almost silver sheen that reflects beautifully as they shimmer under the lights. Their tails are perfectly checker patterned with a deep blue/black pigment and their bright red noses seem to glow brighter than Glo-Lite tetra bodies do.