Hex #558d55 or rgb(85,141,85) in RGB space is the tint of green. It has hue angle of 120.00 degrees, value = 55 and saturation = 40. #558d55 can be obtained by mixing 4 colors: 5 drops of yellow, 3 drops of blue, 3 drops of cyan, 4 drops of black.
Nearest safe hex - #669966. Below you can see the block with #558d55 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #558d55 to the mixer and play with it.