Hex #669000 or rgb(102,144,0) in RGB space is the tint of lime. It has hue angle of 77.50 degrees, value = 56 and saturation = 100. #669000 can be obtained by mixing 4 colors: 3 drops of yellow, 1 drop of red, 4 drops of green, 2 drops of black.
Nearest safe hex - #669900. Below you can see the block with #669000 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #669000 to the mixer and play with it.