Hex #778f88 or rgb(119,143,136) in RGB space is the tint of greenish cian. It has hue angle of 162.50 degrees, value = 56 and saturation = 17. #778f88 can be obtained by mixing 4 colors: 3 drops of magenta, 3 drops of blue, 5 drops of green, 4 drops of white.
Nearest safe hex - #669999. Below you can see the block with #778f88 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #778f88 to the mixer and play with it.