Feature Request: Change color of multiple cards simultaneously

Problem description
As a user i like to change the color of multiple cards simultaneously with the "multi selection tool" to save time when i have to change the color of multiple cards.
Currently there is only the opportunity to change the color separate for each card.

Server Setup Information:

• Wekan Version: 2.16
• Node Version: 8.15
• Docker installation
  • App-Docker
  • MongoDB-Docker