Hex #667d5e or rgb(102,125,94) in RGB space is the tint of grass green. It has hue angle of 104.52 degrees, value = 49 and saturation = 25. #667d5e can be obtained by mixing 4 colors: 3 drops of red, 1 drop of magenta, 3 drops of cyan, 3 drops of green.
Nearest safe hex - #666666. Below you can see the block with #667d5e color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #667d5e to the mixer and play with it.