We had someone run an extra large stop sign into our bright red car.
He claimed that because his wife had left him, he was driving fast (in a relatively undeveloped area on the edge of town with dirt roads and paved roads) and seeing everything through a haze of red.
The cop ticketed him as the vegetation had been trimmed back earlier that week (part of why it was an extra large stop sign in that location). He sold his house and moved before we could get him to pay for the repairs to the vehicle though - no insurance and we didn't have uninsured motorist coverage at the time. We had it in place three days later, but it was too late to cover that accident....
I have seen a lot of people who have started ignoring "red" because there is so much "red" in the environment now - it used to be rare and attention getting in a natural setting. With fire engines, brake lights, traffic signs, traffic lights, store signs, vehicles, and the multitude of other things now that are some shade of red, it's like we just can't pick out one red object from the 50 or so vying for attention.
Which makes it sad that red no longer works as a warning signal to our hard wiring, at least not for everyone.
Granted, some people are more easily overwhelmed than others by competing bids for attention.
I've seen some people use flags or floating balloons tied to toddlers, strollers, and wheelchairs that take something up to where a head would be for an adult of average height, in an attempt to make the toddler, stroller, or wheelchair just a little more visible, especially in a crowd.