Hex #66af55 or rgb(102,175,85) in RGB space is the tint of grass green. It has hue angle of 108.67 degrees, value = 69 and saturation = 51. #66af55 can be obtained by mixing 4 colors: 3 drops of yellow, 3 drops of red, 5 drops of cyan, 4 drops of green.
Nearest safe hex - #669966. Below you can see the block with #66af55 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66af55 to the mixer and play with it.