The hex color #51aae1 is a light color. The web-safe version is Hex
#6699CC. A complementary color is
#AE551E. The grayscale version is
#9F9F9F. A 20% lighter version of the original color is
#84DDFF, and Hex
#1E77AE is the 20% darker color. If the color is saturated by 10%, you get
#49ABE8. If the color is desaturated by 10%, the color
#59A9DA is obtained.