Hex #558c55 or rgb(85,140,85) in RGB space is the tint of green. It has hue angle of 120.00 degrees, value = 55 and saturation = 39. #558c55 can be obtained by mixing 4 colors: 3 drops of yellow, 3 drops of cyan, 1 drop of white, 5 drops of black.
Nearest safe hex - #669966. Below you can see the block with #558c55 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #558c55 to the mixer and play with it.