The Smeds and The Smoos by Julia Donaldson Hard Cover Book

The Smeds and The Smoos is about two groups of aliens - The Smeds (who are red) and The Smoos (who are blue) - who never mix. When Janet and Bill, a young Smed and Smoo, fall in love, their families strongly disapprove, but love conquers all. Janet and Bill not only bring their warring blue and red families together, they also celebrate the arrival of their gorgeous purple baby.