id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc	distribution	status_field
2545	colour, shade, grey, turtle sees	tonyforster	walter	"messing with turtle sees, the mouse would not release the turtle, log shows /0 error

Also, turtle sees is affected by the shade setting, even though what it is seeing was done at default shade.

Traceback (most recent call last):
  File ""/home/olpc/Activities/TurtleArt.activity/TurtleArt/tawindow.py"", line 1494, in _buttonrelease_cb
    self.button_release(x, y)
  File ""/home/olpc/Activities/TurtleArt.activity/TurtleArt/tawindow.py"", line 1518, in button_release
    self.active_turtle.spr.rect.height / 2)
  File ""/home/olpc/Activities/TurtleArt.activity/TurtleArt/tawindow.py"", line 1571, in _move_turtle
    self.lc.see()
  File ""/home/olpc/Activities/TurtleArt.activity/TurtleArt/talogo.py"", line 1455, in see
    color_index = self.tw.canvas.get_color_index(r, g, b)
  File ""/home/olpc/Activities/TurtleArt.activity/TurtleArt/tacanvas.py"", line 596, in get_color_index
    r = calc_gray(r, self.gray, True)
  File ""/home/olpc/Activities/TurtleArt.activity/TurtleArt/tacanvas.py"", line 64, in calc_gray
    return int(((c * 100) - (32768 * (100 - g))) / g)
ZeroDivisionError: float division"	defect	closed	Unspecified by Maintainer	Unspecified by Release Team	Turtleart	Unspecified	Unspecified	fixed			Unspecified	Resolved