Hex #66dc55 or rgb(102,220,85) in RGB space is the tint of grass green. It has hue angle of 112.44 degrees, value = 86 and saturation = 61. #66dc55 can be obtained by mixing 4 colors: 5 drops of yellow, 4 drops of cyan, 5 drops of green, 1 drop of white.
Nearest safe hex - #66cc66. Below you can see the block with #66dc55 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66dc55 to the mixer and play with it.