You asked for it and now they're here: Foreign Legion in the Colonial uniforms they wore in Tonkin and Dahomey.
The Foreign Legion went into Tonkin in 1883, at first wearing their uniforms from North Africa, which were totally unsuitable and soon discarded.
By 1898, three Legion battalions were in Tonkin: IV/2nd RE headquartered at Lao Cai, III/2nd RE at Ha Giang, and II/1st RE at Cao Bang.
A good contemporary account is by George Manington: A Soldier of the Legion: An Englishman's Adventures Under the French Flag in Algeria and Tonquin. Manington served in the Legion from 1890-1895, most of it in Tonkin. The book is available from Amazon.
These figures are from a slightly later period, when the Legion wore the Troupes Coloniales' khaki drill M1901 tropical uniform. These figures could be painted in all-khaki, or with white, uncovered sun helmets and white trousers. Officers wore khaki or white at their discretion.
They carry tent rolls and de Negrier ammunition pouches, as well as the waistbelt "coffin pouches" for the Gras rifle.
These figures can also be used for the Dahomey Campaign of 1892, where they were dressed the same. In Dahomey, there was a battalion of volunteers from the two Legion regiments.
You could also paint them in the earlier period Infanterie de Marine uniforms of dark blue jackets and white trousers and helmets.
Furthermore, since the Marines/Colonial Infantry dressed the same way, these figures cold be used for them as well.
There are eight figures in all: five legionnaires, officer, an NCO, and a bugler. There are two sets: legionnaires and command.
I don't have painted samples yet. They will look like this plate from Martin Windrow's Osprey book French Foreign Legionnaire 1890-1914.
Here are the Legionnaires, set FR-24.