As far as I understand the problem, when importing a character in unity, only his 3D model is added, and the palette that serves as a texture was not added... I added another file for download, this is a palette that is a texture map of this character.
Thank you for evaluating my work) the model was made simple, therefore it is free available. I made it free available, so if you liked the model, you can of course use it in your project) Good luck with your projects)
