Like his father the earl,[4] Viscount Milsington was a racehorse owner; he and his wife were regular racegoers.[5] His grey mare, Tiffany, won the 50-pound[clarification needed] weight-for-age race at Salisbury Races in 1780 and his horse Scarf ran in the 1781 Derby.
He succeeded as the 3rd Earl of Portmore on the death of his father in 1785.
Personal life
On 5 November 1770, he married Mary Leslie (1753–99),[6] second daughter of the 10th Earl of Rothes. Their children included:
Thomas Charles Colyear, 4th Earl of Portmore (1772–1835), who married Lady Mary Elizabeth Bertie and had one son; there were no children from his second marriage, to Frances Murrells.
Lady Catherine Caroline Colyear, who married James Bracknell
The deaths of the couple's two daughters, Lady Mary and Lady Julia, in Bath, within three hours of one another[8] on the same day in 1800, were the subject of a poem by Mary Young Sewell.[9]