Hex #556e5d or rgb(85,110,93) in RGB space is the tint of bluish green. It has hue angle of 139.20 degrees, value = 43 and saturation = 23. #556e5d can be obtained by mixing 4 colors: 3 drops of yellow, 5 drops of blue, 1 drop of white, 3 drops of black.
Nearest safe hex - #666666. Below you can see the block with #556e5d color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556e5d to the mixer and play with it.