Hex #109990 or rgb(16,153,144) in RGB space is the tint of cyan. It has hue angle of 176.06 degrees, value = 60 and saturation = 90. #109990 can be obtained by mixing 4 colors: 1 drop of magenta, 5 drops of blue, 5 drops of cyan, 5 drops of green.
Nearest safe hex - #009999. Below you can see the block with #109990 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #109990 to the mixer and play with it.