This is the 12199th most frequent Swedish word.
rödgrön
Red-green.
Here, 'rödgrön' describes the sweater's physical colors, being red and green.
Jag köpte en rödgrön tröja till min vän.
I bought a red-green sweater for my friend.
In this context, 'rödgrön' metaphorically describes the mix of red and green shades seen in someone's face due to physical effort.
Han var rödgrön i ansiktet av ansträngningen.
He was red-green in the face from the exertion.
In this sentence, 'rödgrönt' refers to a political collaboration between parties identified with red and green colors.