Attach streamers to the tips of wind turbine blades, they'll draw a pretty arc through the sky like gymnastics ribbons. Not necessarily to every turbine in the field, maybe just one in five.
Use the colours from the national flag - you could switch to red for Christmas or green for the spring equinox.
an extra-special look, tie bows in the streamers so that they look like the tails from kites in childrens' books.
Rain sensors would spool in the streamers during inclement weather to stop them becoming sad and droopy.