My favorite silly thing to think about is the idea of Tim having achromotopsia, or total color blindness also known as rod monochromacy. It's not as common as, say, red-green color blindness, but it does have more significant impacts on a person due to its tendency to result in poor visual acuity and day blindness. In other words, people with achromotopsia can't see well in daylight, because they can't perceive colors, so it has a similar effect to being unable to distinguish shapes and colors in darkness.
So basically I just love thinking about totally color-blind Tim, refusing to be even one little bit more careful in the daylight hours because achromotopsia can't stop him. Sleep debt can't even stop him. He'll crash a car if he wants to, it's not like Bruce doesn't have ten more.