I modify the diffuse value through the Inspector, and it seems to be normal,but i don’t know if this is the solution
Do you have same results with this model in Sandbox?
Same.I think it should be caused by diffuse color.
I also think so. You can correct it in 3D editor or just in the code.
@ZoeLeee : I see that you are importing an .obj file. There should be an .mtl file (the material data) that goes along with that. It should be relatively simple as there is just one mesh with a texture.
Open that .mtl file in a text editor and look for a line that starts with "“Kd”. It should look like this :
Kd 1.00 1.00 1.00
If not, replace that line with the above (copy and paste, is fine). and save the file as an.mtl. Now try the playground or sandbox.
The “Kd” defines the diffuse color of the mesh
It has been a long time since I have used .obj files . Always seemed to have small problems with them.
Stay Safe All, gryff 
Yes, all mtl files “Kd” are 0.00. Currently, diffuse can only be modified by code.