Hex #378b80 or rgb(55,139,128) in RGB space is the tint of greenish cian. It has hue angle of 172.14 degrees, value = 55 and saturation = 60. #378b80 can be obtained by mixing 4 colors: 3 drops of red, 3 drops of blue, 5 drops of cyan, 3 drops of green.
Nearest safe hex - #339999. Below you can see the block with #378b80 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #378b80 to the mixer and play with it.