I used a whole bunch of the 2-wire JST inline power connectors
male and
female for my
Logo Glowego project. The product pages say "One wire is marked with a white dashed line. You can't plug these in backwards." My experience with the product is that while the connectors pretty much insure they only fit one way, the white marked wires are NOT necessarily on the same side on Male/Female connectors. I noticed this while wiring them up and ignored the stripe. (rule I do have a number of these (and the 4 wire version) in my shopping cart because they are a great product otherwise.