Hex #66ad4d or rgb(102,173,77) in RGB space is the tint of grass green. It has hue angle of 104.38 degrees, value = 68 and saturation = 55. #66ad4d can be obtained by mixing 4 colors: 1 drop of yellow, 4 drops of green, 3 drops of white, 2 drops of black.
Nearest safe hex - #669966. Below you can see the block with #66ad4d color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66ad4d to the mixer and play with it.