Hex #40686b or rgb(64,104,107) in RGB space is the tint of cyan. It has hue angle of 184.19 degrees, value = 42 and saturation = 40. #40686b can be obtained by mixing 3 colors: 2 drops of yellow, 5 drops of blue, 1 drop of black.
Nearest safe hex - #336666. Below you can see the block with #40686b color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #40686b to the mixer and play with it.