If you have ever used a book of paint chips to decide what colors to paint the exterior of your house, you may have had an unpleasant surprise. Colors that match beautifully in the book can be ugly as a Christmas tie when painted on your house.

Now there's a way to see how your house would look painted in your choice of colors - before you hire the painters. Just send Glidden Paint Co. a photograph of your house and your choices for three separate color schemes. Glidden will create electronic images of your house in the three color choices and send you snapshot-size color prints of the images.What a great idea. And what a shame more people won't be able to take advantage of it. The offer is available from Glidden only on the Prodigy network for personal computer users.

The service has been available to Prodigy members since December, and Glidden is averaging about 100 orders a week for the $40 kit, according to a spokesman for Glidden's advertising agency. One of the good surprises is that lots of the orders are coming from Northern states, where the paint business is normally dead in late winter and early spring.