Anti-slip edging for marble stairs

We are looking for edging for the stairs. Nothing too obtrusive, but something which can be easily seen when coming downstairs. Any advice on suppliers or DIY would be helpful.
Thanks.

We use an anti-slip tape on the stair edges. I was a bit concerned that 'er indoors might slip especially when wet.
We bought it from the Brico in Los Montesinos (the one on the right after the garden centre) and you can cut it to size. It simply sticks to the floor and we have it on each step with a strip at front and back on the wider steps.
Not that expensive and it's been down for the last 4 years or so (still sticking).

Thanks very much for your reply mar cliff, much appreciated, will go tomorrow