Subchapters:

Plotting in color

One of the simplest ways to plot in color is to first define a new color table and then to save the indexes of the color in a variable that can be addressed from everywhere. A system variable will then be used. The following routine can be called when starting IDL (the best would be to include it in the init file).

pro my_colors
defsysv,'!col',EXISTS = col_exists
if not col_exists then $
defsysv,'!col',{black     : 0, $
                white     : 1, $
                red       : 2, $
                green     : 3, $
                blue      : 4, $
                yellow    : 5, $
                magenta   : 6, $
                cyan      : 7, $
                orange    : 8, $
                l_green   : 9, $
                violet    : 10,$
                turquoise : 11,$
                l_blue    : 12,$
                l_red     : 13 $
               }
;        0  1    2   3   4   5   6   7   8   9   10  11  12  13
tvlct,[  0,255, 255,  0,  0,255,255,  0,255,125,125,  0,  0,255],$ ;red
      [  0,255,   0,255,  0,255,  0,255,125,255,  0,255,125,  0],$ ;green
      [  0,255,   0,  0,255,  0,255,255,  0,  0,255,125,255,125]   ;blue
end

Then, you can plot in colors:

IDL> plot,sin(findgen(200)/20.)
IDL> oplot,cos(findgen(200)/20.)^2, col = !col.red
IDL> oplot,sin(findgen(200)/15.), col = !col.blue