The hex color #577ca8 is a dark color. The web-safe version is Hex
#666699. A complementary color is
#A88357. The grayscale version is
#7E7E7E. A 20% lighter version of the original color is
#8AAFDB, and Hex
#244975 is the 20% darker color. If the color is saturated by 10%, you get
#537CAC. If the color is desaturated by 10%, the color
#5B7CA4 is obtained.