I remember that when I was younger I saw sci-fi stuff and art showing air pollution to become so bad that the sky color changed to either redder and brighter or dimmer and dark grey.In other words, the sky is no longer cyan blue.And it seen that plants become to look like black/grey and appear to be dead.Do you think such thing can actually happen?
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I was recently close to a wildfire with a great deal of ash in the air and falling. The sky was dark, and the sun was completely red, and dim enough that you could look right at it. So yes, from personal experience, what you are talking about can certainly happen (although if that happened worldwide it would be a lot like nuclear winter).
That said... The discoloration and temperature drop are both caused by particulates, ie soot. Modern factories don't really release soot into the air, since it's pretty easy to keep out of the atmosphere with a filter. The main climate concern with modern factories is CO2 emission. And CO2 does not alter the color of the atmosphere, it just traps more heat.
So, in conclusion, what you are describing is very unlikely, unless technology and governmental regulations on pollution both regressed significantly. To my knowledge, the only things that could release that much soot into the air is nuclear war or massive volcanic activity.