Thank you for your post.
The video at the link below shuold help shed some light on this issue.https://www.youtube.com/watch?v=GhJCneCQ7ZY&list=PL_je7dD7rzFtMCJVxYtuF-QcJoMy1C8JF&index=3
There is a way to fix it for now if there isn't a texture only material on the material field, which I've put below.
1. Go to/open the SketchUp Paint Bucket Tool.
2. Select the material using the 'Sample Paint' (eye dropper icon).
3. Click on the 'Edit' tab.
4. Select 'Reset Color' and the material will be reverted to the correct value.
Would you be able to please let me know if this works for you?