However, after finishing the installation of this module, everything seemed to go well, so we tried to change the default color of the configuration.

From that moment until now, 

We tried to solve it by deleting and adding again the files of the module, but we don't longer have idea of how to solve it, now the only error message is "500: Internal Server Error".

We greatly appreciate your prompt attention to this critical matter. I am available for any further queries you may have.