Hex #557963 or rgb(85,121,99) in RGB space is the tint of teal. It has hue angle of 143.33 degrees, value = 47 and saturation = 30. #557963 can be obtained by mixing 4 colors: 1 drop of blue, 2 drops of green, 4 drops of white, 5 drops of black.
Nearest safe hex - #666666. Below you can see the block with #557963 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #557963 to the mixer and play with it.