You can set your browser to override the colours if you want. I have found that in the past 11 years, about 1% of people have had issues with the colours. Mostly it comes from a certain combination of video card and monitor.
As for your engine, I assume this is a float carb? If so then the metering seat and needle that controls the level in the bowl are worn. Or the float is stuck. Either way, you need to get a rebuild kit for the carb...