I have an M2 MBA connected to an external monitor. when the MacBook is open and so both screens are on, the external display is a little washed out. I close the lid, and immediately it's more vibrant and colorful. why does this happen?
Not sure if this is what you mean by washed out, but when True Tone is enabled, it gets applied to the external screen when the lid is opened. Essentially, the monitor goes from cool to warm color temperature. Try toggling that setting and see if it helps.