Hex #66c155 or rgb(102,193,85) in RGB space is the tint of grass green. It has hue angle of 110.56 degrees, value = 76 and saturation = 56. #66c155 can be obtained by mixing 4 colors: 2 drops of yellow, 1 drop of blue, 1 drop of cyan, 1 drop of green.
Nearest safe hex - #66cc66. Below you can see the block with #66c155 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66c155 to the mixer and play with it.