Hex #66a84a or rgb(102,168,74) in RGB space is the tint of grass green. It has hue angle of 102.13 degrees, value = 66 and saturation = 56. #66a84a can be obtained by mixing 4 colors: 5 drops of yellow, 5 drops of blue, 4 drops of green, 1 drop of white.
Nearest safe hex - #669933. Below you can see the block with #66a84a color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66a84a to the mixer and play with it.