When I was rear ended riding a regular bike, it was broad daylight and I was wearing a hi-viz yellow long sleeve top and had a yellow bash hat on, 'fraid I don't altogether hold with bright colours / lights means that you will always be noticed.
The expectation that all "vulnerable" road users should wear high viz and be lit up in daylight feeds into the victim blaming mentality where its somehow your fault for being run down, not the responsibility of the driver of the larger, heavier, faster vehicle to be able to stop in the distance they can see to be clear, to have consideration for other road users, and to look where they are bl**dy going.
As a long time motorcyclist I have seen years of arguments as whether you should ride with your lights on in daylight, wear high viz etc and at one time it could be said that it "might" make a difference. Now that all new vehicles have permanent driving lights you lose any advantage because you blend into the sea of lights and it's a bit of an arms race because even low output lights are getting brighter. It used to be said that you should assume that you put on a cloak of invisibility when you get on your motor bike, and ride accordingly. It's a psychological thing. Car drivers are programmed to look for car sized objects particularly in our car centric culture and anything smaller can be overlooked particularly in a quick scan at a junction. As a general rule you have to ride defensively which for a new cyclist who has been used to driving a car takes time to learn. Car drivers take for granted limited vision due to thick safety pillars particularly in modern cars.
It came as a shock to me after motorcycling and cycling for years how many blind spots there were in a car once I learned to drive in 1980, even with the skinny pillars and thin doors which cars had then.
When mixing it with car drivers who mostly have no experience of other vehicles, it is useful to bear in mind that they can't hit you if you're not there, and to constantly be thinking "what if?" and to assume that they are most likely idiots. Keeping a lookout for an escape route is also good. The experience of
@simongt shows that even this can't prevent the unexpected happening. This topic could develop into a thread of its own.
The "differentness" of a recumbent bike or trike (or even an upright trike) or trailer is enough to make most other road users give you a wide berth and so increase your safety (real or perceived) compared to an upright but doesn't change the laws of physics if it comes to the crunch. By all means get lit up, reflect away to your heart's content, fluoresce, wear a helmet, carry a St Christopher medallion, lucky rabbit's foot (not so lucky for the rabbit) your favourite underpants or whatever, all optional. I would like to fly a flag, but in my area the possibility of being trampled by a panic stricken horse outweighs the benefits.
Just remember that the biggest aid to safety is between your ears and that despite what people seem to believe, cycling is not inherently dangerous!