C7 and C9 lights once dominated the Christmas light market, but in recent years, more and more people have switched over to using the little white lights, thinking that the large colored lights of yesteryear can no longer be found. 

It is still possible to buy sets of multicolored C7 and C9 lights (the traditional lights).  You can find C7 and C9 lights at large chain stores, on the Internet and on eBay.  In a typical light set, the bulbs come in colors of red, blue, white, orange and green, but not yellow.  Yet a tree without yellow lights is like a sandwich without bread. 

Why you need yellow

If you're decorating a tree or holiday display using multicolored lights, you need yellow.  Yellow is a primary color and just as essential to any multicolored light set as red or blue or green.  Yellow is a primary color and it adds brightness and sparkle to any holiday display.  Without yellow, your tree looks dull and drab.  See the difference below.

Without yellow lights                     With yellow lights

In addition, yellow lights look great in candles.  Clear bulbs are cold and sterile.  Transparent bulbs are hard on the eyes, white bulbs looked washed out, orange bulbs look like embers, but yellow bulbs really look like flames.  Below, I have included a picture of two candles, one with a yellow bulb and one with an orange bulb.  See how much more realistic the yellow bulb looks. 

In Conclusion...

Fortunately, it is possible to buy yellow C7 and C9 lights at select websites on the Internet and on eBay and they can easily be added to existing light sets.  If you want to use the colored lights this Christmas, you can purchase a set of multicolored lights and then go onto eBay or some other website that sells yellow lights, buy a carton of yellow lights and then add the yellow lights to your light set.