A set of thick Roman curtains in four positions.
The color of the model can be easily edited in the material settings.

Other models of roller blinds and Roman blinds: https://3dsky.org/collection/shared/5237728 

For Corona render it is recommended to install a version at least 1.5 since the glossiness of the materials is configured with PBR in mind.

If you are working on a V-Ray version lower than 3.1 then be careful in the materials in the BRDF section there is a Microfaset GTR ( GGX) if your version is older then the BRDF field will be empty. Choose Blinn Phong or Ward – which is preferable for you.