Hex #405a5d or rgb(64,90,93) in RGB space is the tint of cyan. It has hue angle of 186.21 degrees, value = 36 and saturation = 31. #405a5d can be obtained by mixing 4 colors: 2 drops of yellow, 5 drops of blue, 1 drop of white, 4 drops of black.
Nearest safe hex - #336666. Below you can see the block with #405a5d color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #405a5d to the mixer and play with it.