Adobe Kuler : https://color.adobe.com/fr/create/color-wheel/
Coolors : https://coolors.co/
Colordrop : https://colordrop.io/
Colorhunt : https://colorhunt.co/

Myspace.space : https://mycolor.space/
Webgradients : https://webgradients.com/
Gradients.io : http://gradients.io/