Collectible Card Game Headquarters

Hello,
Excuse my probably very silly question but I tried to find an answer on both forum and faqs of Forge without any success.
Could you tell me what the rainbow layer over card image means? Sometimes when I draw a card it is normal (the picture is normal), sometimes it has a kind of rainbow layer over the picture. This layer stays over the picture even if I play the card. Sometimes it is land, sometimes a permanent. Sometimes I have 2 identical lands with the same picture but one is clear, one with layer. I cannot find anything that this cards have in common.
Thanks,
Jacek

It's a foil card. Right now, AFAIK, they're randomly assigned but I think there is plans to make foil-ness persistent.

Any configuration to turn it off? Pictures looks ugly with this layer.

Moxmox wrote:Any configuration to turn it off? Pictures looks ugly with this layer.

From the main menu, there's a checkbox that says something about Foils. Uncheck.

Thank you. Found and used.