Blue violets are considered an invasive weed because ... grow in your yard might not be such a bad thing. Their tiny green leaves remain green all year long, allowing for some color to remain ...

The new violet LEDs aim to erase this effect ... "However, if we use three phosphors [blue, red, and green-emitting], it is possible to carefully tune the ratios of the phosphors to minimise ...

Flight: longer, narrower wings and shorter tail than the tree swallow; the violet-green has a more fluttering flight style. The tree swallow is larger, entirely greenish blue above, and lacks ...