White.

White is such a summery colour. It's so fresh and pretty. Maybe I'll change my black wardrobe for a white one.

This is what Christian Dior's 'The Little Dictionary of Fashion says about white:

White is more beautiful than any colour for evening. At a ball there are always one or two white dresses which are outstanding. White is pure and simple and matches everything. For day-time it has to be used with great care because it must always be really white and immaculate. If you cannot keep it so it is better not to have it.

But nothing gives the impression of good grooming and being well dressed more quickly than spotless white...

Image via We Heart It