The Mossi flag from EU IV is light orange and dark green stripes, so I think those might work as colours. Anyway, here's a refinement of the Burkinabe idea Hoop was talking about:-
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Mossi Kingdom (Yennenga)
Start Bias: Plains
Capital:

Wagadugu
UA:
Etalons De La Reine
Units that require a specific Strategic Resource gain a +3%

Combat Bonus when attacking for each excess copy of that Resource you possess. +2

Faith from Pastures.
UU:
Nakombse (replaces Knight)
Higher

Combat Strength than the Knight it replaces (25

Strength vs. 20), faster, and starts with both Charge and a unique promotion, "Naam", which allows it to both generate a small amount of

Culture and

Faith when Pillaging a tile and healing additional HP from doing so when close to an enemy City. Vastly more expensive and cannot be bought with

Gold, but may be purchased with

Faith without requiring the Holy Warriors founder belief. If the Holy Warriors belief is selected, Nakombse may be purchased at reduced cost. Upgrades to Cavalry.
UB:
Friday Court (replaces Temple)
+1

Faith. +1

Faith from Bonus, Strategic, and Luxury Resources. Also generates 1 of every yield the Palace (stacks with God-King Pantheon, but does not include the

Tourism yield from the filled

Great Work of Art slot) generates, plus a

Golden Age point, once the Grand Temple is constructed. Costs additional

Maintenance.
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So, this one is a bit more streamlined than the other, focusing more on your mini-palaces and mid-game equestrian antics, with the aristocratic cavalrymen forming expert raiding parties as they did in real life - they even went deep into Malian territory on their little shopping trips. The Friday Court is possibly a little bit broken, but to get the most out of it, you need to pick a slightly lacklustre pantheon in the form of God-King... or just settle near a bunch of Horse tiles and see how well it goes. =]
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EDIT: Here's the flag I was talking about.