The hex color #66a549 is a light color. The web-safe version is Hex
#669933. A complementary color is
#995AB6. The grayscale version is
#717171. A 20% lighter version of the original color is
#99D87C, and Hex
#337216 is the 20% darker color. If the color is saturated by 10%, you get
#65AA45. If the color is desaturated by 10%, the color
#67A04D is obtained.