Hex #407a6b or rgb(64,122,107) in RGB space is the tint of greenish cian. It has hue angle of 164.48 degrees, value = 48 and saturation = 48. #407a6b can be obtained by mixing 4 colors: 1 drop of red, 1 drop of blue, 1 drop of cyan, 1 drop of green.
Nearest safe hex - #336666. Below you can see the block with #407a6b color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #407a6b to the mixer and play with it.