Hex #406e64 or rgb(64,110,100) in RGB space is the tint of greenish cian. It has hue angle of 166.96 degrees, value = 43 and saturation = 42. #406e64 can be obtained by mixing 4 colors: 1 drop of yellow, 2 drops of magenta, 5 drops of blue, 4 drops of green.
Nearest safe hex - #336666. Below you can see the block with #406e64 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #406e64 to the mixer and play with it.