Hex #669e55 or rgb(102,158,85) in RGB space is the tint of grass green. It has hue angle of 106.03 degrees, value = 62 and saturation = 46. #669e55 can be obtained by mixing 4 colors: 5 drops of yellow, 1 drop of red, 5 drops of cyan, 4 drops of black.
Nearest safe hex - #669966. Below you can see the block with #669e55 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #669e55 to the mixer and play with it.