I have just returned from visiting DS and family to help decorate DGC's shared bedroom, DGD, 6, and DGS,3. DGD had most input. She did go through an intensive pink stage, but DDiL tempered it, she might get pink socks and underwear but the line was drawn at the pink Barbie bed in Mothercare and excessively pink girly, in the most cloying sense, toys.
When it came to decorating DDiL thought white would be nice but DGD took over, no, it had to be blue. She and DGS wanted a seaside themed room 'as it is my most favourite place to be'. So they have a red, white and predominantly blue coloured room. However she crumbled slightly when we went to get bedside lamps. DGS has a lamp like a light house with pirate symbols on the lamp shade, hers is pink with a pink patchwork lampshade.
As for answering questions, always answer them, if you do not know say so and then google the answer. Small children need answers but more than anything they need to know how to be able to find things out for themselves. In the past it was reference books and 'Lets go the library and find out'. Now it is google the answer but learn how to distinguish authoritative and reliable sources from those that are anything from the casually inaccurate to the deliberately misleading.