The hex color #669e9c is a light color. The web-safe version is Hex
#669999. A complementary color is
#996163. The grayscale version is
#8B8B8B. A 20% lighter version of the original color is
#99D1CF, and Hex
#336B69 is the 20% darker color. If the color is saturated by 10%, you get
#62A09E. If the color is desaturated by 10%, the color
#6A9C9A is obtained.