My turn to be a bore. Apparently the white boar was the symbol of Richard III. During his reign there were many pubs around England called the White Boar in his honour. However his popularity was waning (due to those pesky nephews in the tower rumours) and when he was defeated in battle by Henry and killed, publicans all over England had a problem with their 'branding'. Fortunately one of Henry's supporters had the symbol of a blue boar and so the problem was solved with a splash of blue paint. Nicely done.