Here You can set color by changing hue, saturation and lightness and watch at complimentary colors at bottom of the page or just click random color.
Basic color:
#cf0c0c; rgb(207,12,12); hsl(0,89%,43%);
black
black
white
white
Complementary colors:
Analogous harmony (H+30):
#cf6e0c; rgb(207,110,12); hsl(30,89%,43%);
black
black
white
white
Analogous harmony (H-30):
#cf0c6b; rgb(207,12,107); hsl(330,89%,43%);
black
black
white
white
Triadic harmony (H+120):
#0ccf0d; rgb(12,207,13); hsl(120,89%,43%);
black
black
white
white
Triadic harmony (H-120):
#0e0ccf; rgb(14,12,207); hsl(240,89%,43%);
black
black
white
white
Split complements harmony (H+150):
#0ccf6f; rgb(12,207,111); hsl(150,89%,43%);
black
black
white
white
Split complements harmony (H-150):
#0c6ccf; rgb(12,108,207); hsl(210,89%,43%);
black
black
white
white
Complement harmony (H+180):
#0ccecf; rgb(12,206,207); hsl(180,89%,43%);
black
black
white
white
Monochromatic harmony (S+30):
#db0000; rgb(219,0,0); hsl(0,100%,43%);
black
black
white
white
Monochromatic harmony (S-30):
#ae2d2d; rgb(174,45,45); hsl(0,59%,43%);
black
black
white
white
Monochromatic harmony (L+10):
#f21c1c; rgb(242,28,28); hsl(0,89%,53%);
black
black
white
white
Monochromatic harmony (L-10):
#9f0909; rgb(159,9,9); hsl(0,89%,33%);
black
black
white
white