So, the answer depends somewhat on what material you used. If you imported the whole model with a material as defined in your 3D authoring tool, I'm not sure you'd be able to. We used the same materials as Firaxis (included in the SDK). WeaponCustomizable_TC for the conventional/magnetic, and M_Master_PwrdWep_TC for the beam. In both cases, you need to define the tint-able area of the model in one of the textures. The MSK texture, Blue color channel, if I recall correctly. Since it's the full channel, you can use grey values to determine amount of tint/pattern. Also, when configuring the material instance in UnrealEd, be sure to enable tinting. For the WeaponCustomizable_TC material, under Switches, enable UseTint and under Pattern, enable Pattern (and perhaps set the Pattern_UVScale if needed). For the M_Master_PwerdWep_TC, there's no toggle for tinting (it's on by default), but the Pattern/ Pattern toggle and Pattern_UVScale need to be enabled. And if you are curious about the difference between the two, the former allows for "metalness" in the alpha channel, while the latter allows for flickering emissive and has "gloss" designed to better match the powered armors. Ok. And how did you make the MSK? I tried making one and only got the stock of the model able to change colors but it's a very faint change and the patterns are almost transparent.