The 5th Regiment of Foot won their hackle by defeating a far larger group of French troops at eh battle of St Lucia in 1780 or so. They took the feathers from the helmets of the fallen French. Years later the British king decided to award all infantry units the white feather. This would have taken away from the 5th's battle hoour of winning their feather. So it was decided that the 5th's feather would be distinguished from the rest by coloring part of it red to show it was earned in battle, or with blood.
The 5th also won their helmets from the French in 1762 at Wilhelmstahl by defeating several regiments of French Grenadiers. They were allowed to keep the helmets as trophies and had enough to outfit the entire regiment. So not only the 5th's grenadiers had bearskins, but the entire regiment had them. In the same battle they captured a set of French colours and were allowed to keep them as well. So they had three colours,a hackle, and helmets all captured from the French almost within a century.