how to do orange arrows?

I figured out how to create red blue and green arrows/circles (shift/ctrl/alt click/drag) in studies, eg see here: http://de.lichess.org/study/C1d46uaR

How to do yellow arrows, like eg. here (position 2): http://de.lichess.org/study/33knmI2A

Are there other possibilities for colors (not that this isnt enough)?

Ok found the answer here:

http://de.lichess.org/qa/423/how-does-drawing-on-the-board-work