You can find 2 material balls both named to easily change material for each object (bidet + wc-flush button).

Toilet and Bidet

Manufacturer: Olympia Ceramica
Model: Crystal
Color: Black & White
Mount: Floor-mounted Toilet & Bidet

Flush

Manufacturer: Villeroy & Boch
Model: ViConnect
Color: Black + White

Bidet Tap

Manufacturer: Villeroy & Boch
Model: Architectura Square
Color: Chrome