Hex #66d666 or rgb(102,214,102) in RGB space is the tint of green. It has hue angle of 120.00 degrees, value = 84 and saturation = 52. #66d666 can be obtained by mixing 4 colors: 1 drop of yellow, 1 drop of cyan, 5 drops of green, 3 drops of white.
Nearest safe hex - #66cc66. Below you can see the block with #66d666 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66d666 to the mixer and play with it.