The hex color #a0091d is a dark color. The web-safe version is Hex
#990033. A complementary color is
#5FF6E2. The grayscale version is
#424242. A 20% lighter version of the original color is
#D33C50, and Hex
#6D0000 is the 20% darker color. If the color is saturated by 10%, you get
#A90319. If the color is desaturated by 10%, the color
#970F21 is obtained.