Hubby & I will be visiting London next November. I’ve jokingly suggested we make some leather collars, like the Marines had so long ago. Hubby laughed off the suggestion, but anyone who works with leather might have a new product to sell.
Like all places, you want to know where you are going and don't go to the dangerous spots (which can also be majority white) in the night time
For the tourist spots it is very safe
I would recommend a nice walk from Victoria Terminus to Buck house to the houses of parliament, then across the bridge to the London war Museum, then back across tower bridge to the tower, then St pauls, The City, then to Trafalgar square and the museums there.