Mosquito Rasbora (Boraras brigittae)
Green Neon Rasbora (Microdevario Kubotai)
Emerald Dwarf Danio (
Danio Erithromicron)
Microdevario nana
Boraras merah
Boraras micros
Boraras urophthalmoides
Looked at this
http/www.fishforums.net/index.php?/topic/418749-nano-fish/ and then searched them to find their sizes so you didn't have to
There were a couple on there that got just a smidge over 2cm, not sure how strict you're holding to that.
*Edit* Sorry I overlooked the you wanting them to be similar to ember tetras. So, red in color, right? ;o