Hex #78928c or rgb(120,146,140) in RGB space is the tint of greenish cian. It has hue angle of 166.15 degrees, value = 57 and saturation = 18. #78928c can be obtained by mixing 4 colors: 5 drops of yellow, 3 drops of magenta, 5 drops of blue, 4 drops of cyan.
Nearest safe hex - #669999. Below you can see the block with #78928c color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #78928c to the mixer and play with it.