Hex #66bf33 or rgb(102,191,51) in RGB space is the tint of grass green. It has hue angle of 98.14 degrees, value = 75 and saturation = 73. #66bf33 can be obtained by mixing 4 colors: 3 drops of yellow, 1 drop of red, 2 drops of cyan, 4 drops of green.
Nearest safe hex - #66cc33. Below you can see the block with #66bf33 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66bf33 to the mixer and play with it.