Hex #66805b or rgb(102,128,91) in RGB space is the tint of grass green. It has hue angle of 102.16 degrees, value = 50 and saturation = 29. #66805b can be obtained by mixing 4 colors: 2 drops of magenta, 5 drops of green, 4 drops of white, 4 drops of black.
Nearest safe hex - #669966. Below you can see the block with #66805b color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66805b to the mixer and play with it.