The hex color #a21c05 is a dark color. The web-safe version is Hex
#993300. A complementary color is
#5DE3FA. The grayscale version is
#414141. A 20% lighter version of the original color is
#D54F38, and Hex
#6F0000 is the 20% darker color. If the color is saturated by 10%, you get
#AC1800. If the color is desaturated by 10%, the color
#98200B is obtained.