What do you class as not a lot of pages?
Page count can be increased, though.
Do you have a Title Page?
That can be followed by a blank.
Do you have a Copyright page?
So can that.
It is also a good idea to have consecutive pages in colouring books blank also.
I would assume page count also needs to be divisible by four.
Watch what option you select in Create, because if you want an ISBN and Distribution, not all options can have them. (The ones with the tick can.)
US Letter Perfect Bound Paperback is a good size, and can have an ISBN, but you will need to get your page count to at least 32.
The paper Lulu's printers use is often thicker and whiter than is found in most mass printed books.
And oh, you can always create more art