I've added colours and numbers to the groups of soldiers to make it easier to discuss them. You can see the original photo without any colours here.
The numbers below match the numbers on the photo, and r / g / b refer to the colours. Initials identify who submitted the information: SD - Stephen Davies.
- 3-g : Boy Scouts (SD)
- 12-r : American sailors (SD)
- 15-g : Scots in kilts and Tam-o-shanters (SD)
- 24-b : Group with dark bands around WP helmets, a detachment of RHKP (SD)
- 25-r : Sikh constables of RHKP (SD)
Stephen explains the WP Helmet:
WP = Wolseley Pattern (Foreign Service) Helmet. It had a longer, wider rear brim to shade the neck. It's still the full parade dress helmet of the Royal Marines.