Not as rare as they used to be, and my phone camera isn't up to capturing them, but I have 4 Bolivian Orange "Lemon" Tetras. Stunning colours, especially the touches of true red on them. Unfortunately they don't really like each other, and hide out in the plants, staking out separate territories. They declare a truce at feeding time, and come together then.
Interesting to consider that if I had more, would they shoal? My tank is 121cm long / 240 litres, so might not be able to afford that experiment!