JazakAllah - Thank you for the kind wishes Sir 
I had no idea that white colour had its own challenges... I am finding very small black spots (sometimes a whole bunch of them together) on the paintwork if I leave the car without putting the top cover and they don't wash off either. Quick detailer helped removing them but some of them leave a yellow mark on the paint. I hope its not Artillery Fungus 
The other thing black tar like spots gathered together on the under side of the bumper. Don't know about them either.
I would be grateful if someone can share their experience with something similar and what solution worked for them.