[cairo] Problem in using cairo_set_source_rgb

[ken carlino]

Hi,

I am try to use cairo_set_source_rgb() to set the color to lime green.
When i set the rgb to 50, 205, 50, from here, it is lime green:
http://www.pitt.edu/~nisg/cis/web/cgi/rgb.html


But nothing shows up. Here is my code:
// does not work (nothing shows) when  I use lime green
      cairo_set_source_rgb(cr2, 50.0, 205.0, 50.0);
// works when i set the color to red
	    //            cairo_set_source_rgb(cr2, 1.0, 0.0, 0.0);
            cairo_stroke(cr2);

I appreciate if someone can help me with it. It works if i set it to
red (1.0, 0.0, 0.0).

Thank you.