Hex #40999f or rgb(64,153,159) in RGB space is the tint of cyan. It has hue angle of 183.79 degrees, value = 62 and saturation = 60. #40999f can be obtained by mixing 3 colors: 3 drops of cyan, 2 drops of white, 3 drops of black.
Nearest safe hex - #339999. Below you can see the block with #40999f color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #40999f to the mixer and play with it.