Hex #66dc80 or rgb(102,220,128) in RGB space is the tint of bluish green. It has hue angle of 133.22 degrees, value = 86 and saturation = 54. #66dc80 can be obtained by mixing 4 colors: 1 drop of yellow, 2 drops of cyan, 4 drops of green, 3 drops of white.
Nearest safe hex - #66cc99. Below you can see the block with #66dc80 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66dc80 to the mixer and play with it.