I have a step down from a stoop outside my front door. I want to mark
it for visibility, especially in dim light. (I'll be putting up
lights, but that'll still be a lot less than sunlight.)

What's the best way to mark it? (This is hard to google because words
like "step" and "safety" get too many extraneous hits.) Upper? Lower?
Riser? Paint? Color?

I know from one experience that this can be tricky. I have a similar
step inside, covered by turquoise (sort of) carpet. I put a throw rug
on the upper part. Made it quite visible, yet I tripped every time I
went down. Moved the throw to the lower, and it works great. I still
haven't figured out why.

Edward