http://www.limov.com/colour/schemes.lml is a colour selection tool for seeing close and related colours (for web use but just as handy for home decor ) for your sort of problem. Read the details and as you change the selection on the 'swatch' the samples alter.
Neutral walls with one as a colour accent is the current in look - even white on 3 and cream / beige accent on a 4th might be the ideal.
This makes the effect of the curtains / carpet - which are complimentary colours anyway - the major colours in the room - don't detract from the main colours and don't go for opposites in the colour chart - unless you are really brave and can stand the bold colour scheme, but not recommended.
Or go here:
http://www.mycolour.com.auand you can even colour the curtains to the same as yours and then add the carpet colour, walls and so on - day or night lighting etc. have fun . .