The hex color #b8303e is a dark color. The web-safe version is Hex
#CC3333. A complementary color is
#47CFC1. The grayscale version is
#626262. A 20% lighter version of the original color is
#EB6371, and Hex
#85000B is the 20% darker color. If the color is saturated by 10%, you get
#C12B3A. If the color is desaturated by 10%, the color
#AF3542 is obtained.