I would paint the walls white! It will contrast nicely with the timber window frames. It will also complement the cream. Go white! Post an after photo if you can.

Both so close it doesn't matter. Aluminium is better if it's thermally broken.

The psychology within your home will be more affected by being in an environment you like and feel comfortable with rather than someone elses thoughts. It's really a style choice - do you want a softer look - consider your furnishing styles and preferences. The darker options are good for crisp and contemporary such as in full height multi paned steel Criffal windows. Try Google and Houzz for pictures. A good compromise is silver pearl which is soft but also contemporary.

Hi Belinda - a photo would help us understand your issue. Is the aluminium bare? No paint finish? Many cheaper homes have aluminium windows with a very thin aluminium frame. Is this like yours? I don't think there are any products to improve the proportion of the window frames as they may block the open and closing of each window. I think the only solution would be to replace the whole window, either with a new timber window which has more traditional proportions, or one of the wider frame profile aluminium windows, however the labour involved in fitting new windows makes it an expensive exercise. Trend Windows have a good range of timber and aluminium windows if you want to compare window frame proportions: http://www.trendwindows.com.au/?gclid=CjwKCAiAt4rfBRBKEiwAC678KYIKD_bwdMsJK52Pqe_-kBaEKLbVuE8QTnvFvUHexA5IzGpfpNoSIBoC-zYQAvD_BwE Best of luck, Dr Retro of Dr Retro House Calls