Flat design is a newish term for both print design, web design and mobile operating system design.
Flat web design refers to a design form that does away with busy-looking patterned textured backgrounds, drop shadows around lettering and boxed sections within a web site. This type of appearance creates a very clean looking websites and image quality from LED LCD monitors, tablets and smartphones has increased, shadows and other techniques used partly to make details stand out on small displays or low resolution displays, are no longer needed. As a result, non-flat designs are slowly being dropped in styling decisions, in favor of simpler, cleaner looking, more colorful designs.
As the flat design trend grows some color types have also been popular (see Flat UI Colors) and green is one of them.
So here is a showcase of websites with beautiful flat UI color green.
Flat UI Pro
Moreno Di Domenico
Martijn van den Broeck
Pascal van Gemert