Again on file size

Hi, I am quite confused about the file sizes.
A new created scenario made from the standard architectural template saved after deleting the Laura component and all the associated materials takes about 71KB. Is it correct?

And what about materials (colors)?
I found that an important contribute to the final file size comes from the material used, in numbers and types; question: a pure RGB color should require much less space than a texture, I presume, but in reality a palette of some tens of pure colors takes several hundreds of KB. Am I wrong? And again, if I use the same color or material in a number of different groups/components, did they count as one or are they summed?
Thanks and please excuse me for my English.