Hex #556f55 or rgb(85,111,85) in RGB space is the tint of green. It has hue angle of 120.00 degrees, value = 44 and saturation = 23. #556f55 can be obtained by mixing 4 colors: 2 drops of yellow, 3 drops of red, 5 drops of cyan, 5 drops of black.
Nearest safe hex - #666666. Below you can see the block with #556f55 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556f55 to the mixer and play with it.