Q:

In this sentence, Atmosphere vs Atmospheres?

Here's a sentence written in my book.

The atmosphere in the two parks is completely different. 

As there are two parks that the writter want to compare, why is not plural form of atmospheres put instead of atmosphere? If that is the case, I shoud change 'is' to 'are', right?

The atmospheres in the two parks are completely different.

A:

Actually,  I think the singular "atmosphere" is the better choice here:
The atmosphere in the two parks is not the same.
It implies that each of the two parks has one and only one atmosphere, and that these atmospheres are dissimilar.  
The rooms are not (of) the same color.
The color of the rooms is not the same.
If we say
The colors of the rooms are not the same.
we could mean that each of the rooms has more than one color, and the two rooms are dissimilar with respect to their colors.  One room is white with blue trim, and the other is yellow with green trim.

