Blue could also mean dark green, violet, black or brown. The ancient Greek word for a light blue, "glaukos", also could mean light green, grey, or yellow. The Greeks imported indigo dye from India, calling it indikon. They used Egyptian blue in the wall paintings of Knossos, in Crete, (2100 BC). It was not one of the four primary colours for Greek painting described by Pliny the Elder (red, yellow, black, and white), but nonetheless it was used as a background colour behind the friezes on Greek temples and to colour the beards of Greek statues. The Romans also imported indigo
Ischnura erratica have blue bands dorsally, segments 3 to 6 have narrow yellow rings and there is a large blue dorsal patch stretching from segments 7 or 8 to segment 10. The tip of segment 10 is extended into an upward-pointing forked tail. The female has two colour phases. One is similar to the male but with duller eyes and greenish-blue replacing blue. The other has pale patches on the head, a greenish thorax, and a black abdomen with narrow green rings at the base of some segments. Immature females have dull orange patches on head and thorax. "Ischnura erratica" is native