You can't go wrong with Dulux Natural White, it's the perfect neutral white, (like a milk white?) not warm, not cool, and no dated creamy undertones, looks perfect everytime I've seen it. I like Antique White USA for older homes (it looked great in our old Victorian home), but I sometimes find it too creamy. But consider your flooring too. If you have warm coloured timber floorboards for example a Natural White or warmer would work and would make Lexicon for example look too crisp.

We recently updated an apartment to sell and got great feedback from the buyers on the paint - Dulux 1/4 Lexicon low sheen on walls and Vivid White high gloss on doors, picture rails and trims.

Any poorly lit room is going to throw blue or purple. It's not the paint colour it's the light spectrum and the quality of the light that's making it into the room. Go outside and look at any area of the yard that's shaded. Our brains tell us that shadow is black, but if you really look at the colour, not what you know about the colour, most shadows are a shade of blue, because that's the light spectrum occuring there. Artists know this, if you look at how they paint shadows they are almost always using a shade of blue or purple to do so. So what can you do about it? It's not usually a good idea to paint a dark room that doesn't get much natural light white or near white. That only serves to highlight how dismal the natural light in the room is since what you are getting is a dose of the light spectrum in that area. I had a very dark room with such low levels of natural light (owing to overgrown trees directly outside) that you needed the light on during the day to see anything. I painted that room a very deep shade of blue. Far from looking cold and dark, it became a very cosy and delightful room. Work with the light you have, rather than trying to fake it. Dark rooms actually look best painted an intense shade. The lack of natural light ensures that the colour doesn't overpower and instead ends up looking inviting. You can paint poorly lit rooms shades that you could never get away with in brightly lit rooms. But since you've already painted it, what you can do is put some very intense furnishings in there. Use colour blocking to draw attention away from the wall colour. You have predominantly blue light in that room. Also a warm daylight lamp will help.

Semi-gloss paint is a bit more robust than matt in terms of not getting chipped. (eg. by vacuum cleaners, moving furniture, kid's schoolbags, dogs etc). If you're talking skirting boards/architraves then it's a more pragmatic choice. For cornices: it comes down to personal preference. I extended the ceiling white down onto mine, because I didn't want to highlight them. No right or wrong answer though.