I quite like the colour of your tailpipe in the picture - a natural phenomenon or engineered?
Natural, somewhat, the plug lead fell off after a long run, just simply came off, I limped it home about 1 mile, on the one cylinder, the exhaust changed colour as I expect the heat in the exhaust was igniting the unburnt fuel.
Engine light came on, then once it was fixed drove approx. 2 miles, it went out again.
Now just need to pull the other cap off once hot!!!