Hex #00556f or rgb(0,85,111) in RGB space is the tint of bluish cian. It has hue angle of 194.05 degrees, value = 44 and saturation = 100. #00556f can be obtained by mixing 3 colors: 2 drops of blue, 3 drops of cyan, 5 drops of black.
Nearest safe hex - #006666. Below you can see the block with #00556f color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #00556f to the mixer and play with it.