I imported a SketchUp COLLADA (.dae) file from 2017 SketchUp Make, and imported it into Unity. I then clicked "Use External Materials" and the colors began to load. But I noticed quickly that one of the wings of my imported B-29 was Dark Gray, while the other way a proper color. Random parts, such as the front engine housing piece, were also dark gray. Parts of my advanced dials were also dark gray, and I immediately decided that there is now ay that I am going to manually go in and fix every single dark-gray material, but at the moment, I found no alternative.
I began with the wing. I went to assign the material that I used for the other wing, which was white, to the dark gray wing, but I found out that the other wing already had that material in use. And when I went to assign a different white color, absolutely nothing changed, aside from the fact that the wing now claimed that it had that color in use. Is there a fix for this problem? I could try importing as a .SKP file, if the reason for the issue is something to do with the COLLADA (.dae) file.
What I had was 2 wings. they were both components in SketchUp, so whatever I did to one applied to the other, Then I made them unique before importing to Unity. The Wing that won't work right is the one wing that had the USAF Insignia on it. But I doubt this is the problem, because all engines on that wing were also not colored correctly, whereas the other wing was fine. Those engines were also components, but were also made unique before the import.
Each wing has 9 groups inside of it. The other wing is identical in this sense. I imported the file from file explorer by dragging the file from file explorer and dropping it into unity.
This is what the plane looks like in Unity:
My apologies for the crude handwriting, it is difficult to draw with a touchpad. In the image, I numbered the incorrectly-colored parts visible in the image (Right/Left references are perspective to image)
1. Left Wing. Color: Dark gray. Color intended: White.
2. Propeller blade hub. This is the part that all propeller blades are connected to. Both hubs on the two propellers on the Left Wing are colored incorrectly. Color: white. Color Intended: Grey.
3. Pistons. All piston components, such as the pistons, securing poles, and piston heads are not colored correctly; same on the other engine on the Left Wing. Color: White. Color Intended: Grey pistons, darkish-grey piston heads, and copper-orange securing poles.
4. Cowl Flaps. In the image, this appears to be a stripe in the engine. Same with the other cowl flaps on the other engine on the Left Wing. Color: Dark gray. Color Intended: White.
5. Propeller blades. All 4 propeller blades on both engines on the left wing are not colored correctly. Color: White. Color Intended: Black, with yellow tips.
6. Right-Wing Pistons. Most piston components, such as the pistons heads and securing poles are not colored correctly. Same with the other engine on the Right Wing. Color: White Piston Heads, Grey Pistons, Almost-Black Gray in the lines on the pistons, white securing poles. Color Intended: Grey pistons, darkish-grey piston heads, and copper-orange securing poles.
7. Front Engine Casing. The same error is in the other engine's front engine casing on the Right Wing. Color: Dark Gray, with an apparent shine coming from beneath the part, which shouldn't be happening (the directional light is above the engine part). Color Intended: White.
8. Rear Engine Casing. The same error is in the other engine's rear engine casing on the Right Wing. Color: Dark Gray, with an apparent shine coming from beneath the part, which shouldn't be happening (the directional light is above the engine part). Color Intended: White.