All my bikes have tyres with reflective sidewalls - Schwalbe and Vittoria. This has been the case since 2014. I'm not that familiar with what's on the market and what people typically use but my own experience is that the tyres I want have the reflective sidewalls.
Having seen other reflective tyres caught in the headlights of vehicles (either me as a passenger or on my bike), and also mine in the beam of my head-torch when camping, then as far as visibility goes, they're very effective and immediately recognisable.
With the tyres, my dynamo lights, rear reflector (and sometimes a front one), pedal reflectors and any reflective detail on my clothes and bags, I feel no need for additional side lighting.
I can be riding with a hi-viz gilet and lights on in the day-time and drivers still hit or near miss me (usually on a priority segregated cycleway by school-run drivers coming out of side roads and entrances). At night-time, the treatment and "respect" I get from drivers is elevated to a much higher level. Personally, I think that if you have the full legal compliment of lights and reflectors, together with reflective tyres then you are as good as you're going to get without adding confusing and ambiguous elements into the mix.
