Hex #66bb44 or rgb(102,187,68) in RGB space is the tint of grass green. It has hue angle of 102.86 degrees, value = 73 and saturation = 64. #66bb44 can be obtained by mixing 4 colors: 4 drops of yellow, 2 drops of red, 4 drops of cyan, 5 drops of green.
Nearest safe hex - #66cc33. Below you can see the block with #66bb44 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66bb44 to the mixer and play with it.