Hex #66b261 or rgb(102,178,97) in RGB space is the tint of green. It has hue angle of 116.30 degrees, value = 70 and saturation = 46. #66b261 can be obtained by mixing 4 colors: 3 drops of yellow, 4 drops of blue, 5 drops of green, 3 drops of white.
Nearest safe hex - #669966. Below you can see the block with #66b261 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66b261 to the mixer and play with it.