Analogous colours like red and orange sit side-by-side on the colour wheel; complementary colours sit opposite each other.
This issue’s cushion cover project uses a square tetrad scheme, which takes two pairs of complementary colours, evenly spaced around the colour wheel, and places them together. To prevent this combination from becoming overpowering, look at using different tints and tones of the selected shades. The resulting effect is enticingly colourful but pleasingly complementary. See below for more combos to try.