Recently I needed to color streamlines with exact color (e.g. RGBColor[0.1,0.478,0.5]). The help (http://reference.wolfram.com/language/ref/StreamColorFunction.html) suggests, that this can be achieved by setting StreamColorFunction to some value ("The function specified by StreamColorFunction must return color directives such as RGBColor and Hue or named colors such as Red and Blue."), however in the examples the only option used is "hue", which produces rather fancy colored streams for me (?). I'd like to have all streams e.g. Red, or Yellow, but all of the following codes:
StreamPlot[{x, -y}, {x, -1, 1}, {y, -1, 1}, StreamColorFunction -> Yellow]
StreamPlot[{x, -y}, {x, -1, 1}, {y, -1, 1}, StreamColorFunction -> Red]
StreamPlot[{x, -y}, {x, -1, 1}, {y, -1, 1}, StreamColorFunction -> RGBColor[0,0,0]]
produces default blue streamlines, instead of yellow, red or black (there is a slight possibility that I'm color blinded since today, but I doubt it :)). Why is the StreamColorFunction behaving this way? Is there a possibility to color streams with any color I like? Any help'd be much appreciated.