The Collector Series is a range of miniatures already painted by an artist.
The model is already painted and is as seen on the pictures. No modifications can be done.
For more information on the model itself, you can check the links provided to have scales

Model painted by Maxime Croteau -  https://www.instagram.com/madmaxminiature/.

Model:  

Grinkle the Goblin King by  yasashii kyojin studio

3D Printed by MadMaxMiniatures in high quality resin and stands 80mm high from bottom of the plinth to the top of the sword hilt.