This detail from a photo of the quarter guard of the 20th Hussars c1910 shows a guard in dismounted review order, wearing a busby and carrying the new issue cavalry sword introduced in 1908.
Next to him is a ‘stick man’ wearing dress uniform but with a red forage cap also issued in 1908 for other ranks. He also has a brown leather bandolier.
As with the officer’s cap, the forage cap is scarlet rather than crimson.
History of the 14th/20th King's Hussars 