this model uses vertex coloring for shading and coloring in stuff, the way i got the colors to display close to how they are in crashedit (the program i used to rip it) goes as so...

in general, what you want to do is first, change the surface from principled bsdf to emission and change the strength to 4.6, then add both a color attribute and mix color node. change the settings on the mix color node from mix to multiply and set the factor to 1, then connect the color node on "color attribute" to b, the color node on the texture to a, then connect the result to the color node on "emission". you also want to set the texture filtering from linear to closest.

for some materials, you need to tweak the settings on a case by case basis

for textures with transparency (such as the feathers), keep the surface as principled bsdf, set the base color on the principled bsdf to black if it's not already. add the other nodes as you would normally, but connect the result to the emission node on the principled bsdf, and set the emission strength to 4.6. you also want to connect the alpha from the texture to the alpha on principled bsdf, then change the blend mode to alpha clip.

hope this helps (: