Hex #99e999 or rgb(153,233,153) in RGB space is the tint of green. It has hue angle of 120.00 degrees, value = 91 and saturation = 34. #99e999 can be obtained by mixing 4 colors: 1 drop of yellow, 1 drop of cyan, 1 drop of green, 2 drops of white.
Nearest safe hex - #99ff99. Below you can see the block with #99e999 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #99e999 to the mixer and play with it.