I can think of others such as …
Orange and denim blue
Pale yellow and soft blue
Lime and turquoise
Mauve and brown
These combinations and many others give you a feeling. They work together in a special way.
In this rug I started out knowing the combination of colours even before I decided upon the subject. Red roses are a favorite of mine to hook so they were a natural compliment to the black and white pots. In the long thin rug I chose a coral for the pot just to change it up because I knew that coral and red always work well together in my rugs.
The stems needed to be noticeable and stand out from the background but I did not want their curvy nature to overtake the rug. If I had chosen a bright colour that is all you would see. The deep green real works well I think.
Sometimes colour is your first inspiration!