2 cycle, how much visible smoke is "right"?

I am a bit worried when adjusting the mixture (carburetor) on a 2 cycle engine that it will be too lean and that can damage the engine due to a insufficient lubrication. On the other hand, too rich means less power and more visible smoke.

Is there any useful information that can be gathered from looking at the exhaust smoke out of a small 2 cycle (e.g., on chainsaws)? This question assumes a fairly modern engine designed to work on 50:1 or 40:1 mixtures, not 32:1. That noted, I'd suppose the 40:1 would smoke more than an equivalent engine running on 50:1. Is there any real difference, i.e., what is the risk/damage of running 50:1 in an engine that calls for 40:1? I may be willing to accept faster wear for less smoke/pollution. That is on a low cost unit that get light use may take 10 years to accumulate 100 hours. So if such an application/use is the case running a 40:1 engine at 50:1 may mean it will exhibit troublesome wear at 200 hours of use. I'd say that's good enough for me to run the engine will less smoke and smell.