blue and orange

In color theory, blue and orange are complimentary - blue as a primary and orange as a secondary color. They are opposite each other on the the color wheel. Complimentary in this context means they contrast strongly.

In design palettes, primary and secondary colors are bold. They're vibrant. Web designers, painters, and other color designers much prefer subtler shades. Put complimentary primary/secondaries together and the result is an object that attracts the eye, is instantly recognizable, is garish.

Such complimentary color combinations have a use. It's the instant recognition property that has most value. Particularly where the object is in motion: jockeys in horse races for example, or professional bike riders.

In choosing its primary/secondary, Rabo probably didn't have to consider long before settling on blue (out of the red/white/blue national flag of the Netherlands) and orange (for the House of Orange, the nation's royal family).

I wonder why the colors of the high school I attended are the same (or pretty much the same, I think the blue is a little darker than Rabo blue).

{Image sources: (1) Letterluch Teksproductivies.
(2) TheJournalNews. Caption: "Briarcliff's Meghan Murnane and Pleasantville's Airelle Schneeweiss battle for a rebound in the first half at Briarcliff High School on Jan. 14, 2005. Pleasantville won, 62-57.: (Matthew Brown/The Journal News)}