The most colorful Vieja are the big three: Melanura, synspillum and bifaciatas. The big three carry similar rainbow color pattern of red, orange, yelow, blue, green and black in different shades and distribution. The yellow base makes the big three appear gold plated, and none other Vieja carry gold color. There is on going debate on whether melanura and synspillum are one and the same speices with different color morph. I have all three of them, and my melanura has distinctly more elongated body than syns and bifas. The bifas has similar body shape as the syns, but distinctly red dotted color pattern the other 2 are lacking . So in my observation, all three look similar enough to stand out from the rest of the Vieja gang, yet disimilar enough form one another to be distinct species.