Light blue and white is a classic colour palette for weddings. For a more striking combo, you can also combine two or three shades of blue pairing them with two or three other shades of white (ivory and pearl for example).
This way you and your guests can have a well-deserved visual variety without having too many different colours in your palette.
For a better use of your colour scheme, you should choose one colour as a base and the other as an accent, ideally the lighter colour in the scheme must be the base for the chicest decoration look.
It doesn’t mean the opposite would be wrong, you would just need to pay careful attention to see if you’re not overdoing it.
This palette is especially interesting to be used in a winter wedding since it would look a bit too cold and not very stimulating in the warmer months.