Hex #66a377 or rgb(102,163,119) in RGB space is the tint of bluish green. It has hue angle of 136.72 degrees, value = 64 and saturation = 37. #66a377 can be obtained by mixing 4 colors: 1 drop of blue, 3 drops of green, 4 drops of white, 2 drops of black.
Nearest safe hex - #669966. Below you can see the block with #66a377 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66a377 to the mixer and play with it.