Both. They can't differentiate between red/orange/yellow, can't differentiate gr...

A_Parr on Nov 17, 2019 | parent | context | favorite | on: Tetrachromats: people who see colors invisible to ...

Both. They can't differentiate between red/orange/yellow, can't differentiate greens from grays, but can see further into UV at the cost of not being able to see as deeply into red as you can.