Hex #558a55 or rgb(85,138,85) in RGB space is the tint of green. It has hue angle of 120.00 degrees, value = 54 and saturation = 38. #558a55 can be obtained by mixing 4 colors: 3 drops of yellow, 1 drop of red, 4 drops of cyan, 4 drops of black.
Nearest safe hex - #669966. Below you can see the block with #558a55 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #558a55 to the mixer and play with it.