An equal land area projection of the 10,444 wards of the 1981 census - software by author on an Archimedes computer.
This distribution illustrates use of the three colour scheme well. The mixtures of English and Scots as purple, and English and Welsh as orange, show up nicely on their respective borders. The higher than usual proportions of Scottish and Welsh lifetime migrants in and around London colours that area in greens. The white patches are mainly American airforce bases or the unpopulated mountainous areas of Scotland. On the corresponding cartogram of this distribution, the white shades colour large areas of immigration inside the cities, which are not apparent here.