When Gato del Sol came out of the blue to win the 1982 Kentucky Derby, he eradicated the longstanding prejudice against colts who prepare for the Derby in California. But Easterners may feel safe in reviving that prejudice this year.

The West's best 2-year-olds of last season are both out of action, one permanently, one temporarily. The brilliant filly Landaluce is dead and the champion colt Roving Boy has three screws holding together a bone in his foreleg, after suffering a training accident that will sideline him for months.

Behind these outstanding individuals there was not a great deal of depth. Some of the colts aspiring to stardom competed in the first significant 3-year-old stake of the winter at Santa Anita this afternoon, but the race only verified their mediocrity.

Naevus, a colt who had won his only two starts in smashing fashion, was the even-money favorite to win the seven-furlong San Vicente Stakes, and on the backstretch he found himself sitting behind two faint-hearted speed horses who were battling for the lead. He moved up into contention on the turn and then--nothing.

The two speedsters kept on going, with Shecky Blue defeating Full Choke by a neck, with Naevus 2 1/2 lengths behind them. Since the 1-2 finishers have pedigrees that suggest they would need an oxygen tent if they attempted to go the Derby distance, there was clearly no Gato del Sol in this field.

Who are the best Derby-age colts on the West Coast? The pro-tem leader of the group is Fifth Division, a stoutly bred colt who showed considerable precocity last fall and then rallied to finish third in the rich Hollywood Futurity, two lengths behind Roving Boy in the performance that earned him the Eclipse Award. Desert Wine, who finished second in that stake, had run several good races against Roving Boy, but his front-running style and his pedigree do not suggest that he is a classic-type horse.

The most promising newcomer who has appeared at Santa Anita this winter is a colt named Silent Fox, who made his racing debut this afternoon. He broke from the No. 1 post position and was forced to race on the deep, disadvantageous rail all the way, but nevertheless scored an impressive victory, running just about as fast as the more seasoned colts in the stake did.

Silent Fox's connections and bloodlines won't hurt him. Trained by four-time Eclipse Award winner Laz Barrera, he is a full brother to Affirmed, who spent the winter in California and then went East to win the Kentucky Derby.