Hex #66a21a or rgb(102,162,26) in RGB space is the tint of olive. It has hue angle of 86.47 degrees, value = 64 and saturation = 84. #66a21a can be obtained by mixing 4 colors: 2 drops of yellow, 2 drops of red, 1 drop of cyan, 5 drops of green.
Nearest safe hex - #669933. Below you can see the block with #66a21a color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66a21a to the mixer and play with it.