While a denim button down can be worn with jeans in a different shade, green pants provide a much better contrast.
If you do choose to wear chinos and a blazer or sports coat, be sure to choose formal leather shoes and maybe even sharpen things up with a necktie.
Pair them with olive green cropped pants.
You should know that green color blends great with red, yellow, blue and neutral colors such as black, white and brown, so you can boldly choose button down shirts or blouses of these colors.
Olive This combination would be too much of the same thing.
Though both of them are dark colors, black can complement whatever color you wear with it.
Choose a lighter shade for your shirt and go for a darker tone for your pants.
When going for stripes, match the pants with the shade of the stripes or go with the palette at the background.