Hex #99c880 or rgb(153,200,128) in RGB space is the tint of grass green. It has hue angle of 99.17 degrees, value = 78 and saturation = 36. #99c880 can be obtained by mixing 3 colors: 1 drop of red, 4 drops of green, 5 drops of white.
Nearest safe hex - #99cc99. Below you can see the block with #99c880 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #99c880 to the mixer and play with it.