Hex #66cb4f or rgb(102,203,79) in RGB space is the tint of grass green. It has hue angle of 108.87 degrees, value = 80 and saturation = 61. #66cb4f can be obtained by mixing 4 colors: 5 drops of yellow, 1 drop of magenta, 4 drops of cyan, 5 drops of green.
Nearest safe hex - #66cc66. Below you can see the block with #66cb4f color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66cb4f to the mixer and play with it.