Interior Trim Codes

The interior trim color code is a 3-digit number. Those not checked under Bucket are bench seat styling.
There may be additional interior codes for Oshawa-built Chevelles as I have no source to reference.
Atlanta, Framingham, and Kansas City also included a -A or -B to denote bench or bucket seat. When optional headrests were ordered the -A or -B gave way to -S for bucket seats and -E for bench seat; Baltimore, Fremont, and Oshawa did not.

CodeColorBucket
705Plum Royale Cloth, Antique Plum Imitation Leather (sport sedan only) 
720Medium Fawn Imitation Leather 
723Medium Bright Blue Imitation Leather 
724Medium Blue Redmond Cloth, Medium Blue Imitation Leather 
726Medium Blue Rio Cloth, Medium Blue Imitation Leather 
727Medium Blue Pattern Imitation Leather 
728Medium Blue Roncina Cloth, Medium Blue Imitation Leather 
729Medium Blue Imitation Leather 
730Medium Blue Royale Cloth, Medium Blue Imitation Leather (sport sedan only) 
731Medium Bright Blue Imitation Leatherx
738Medium Blue Imitation Leatherx
746Dark Maroon Roncina Cloth, Dark Maroon Imitation Leather  
747Medium Red Imitation Leather 
750Medium Red Imitation Leatherx
757Black Pattern Imitation Leather 
759Black Roncina Cloth, Black Imitation Leather 
761Black Imitation Leather 
762Black Royale Cloth, Black Imitation Leather (sport sedan only) 
763Black Imitation Leatherx
764Black Rio Cloth, Black Imitation Leather 
766Medium Red Imitation Leather 
748Medium Red Imitation Leather (El Camino only) 
749Medium Red Imitation Leather (El Camino only)x
750Medium Red Imitation Leatherx
760Black Imitation Leather 
761Black Imitation Leather 
762Black Imitation Leather (El Camino only)x
763Black Imitation LeatherX
764Black Rio Cloth, Black Imitation Leather 
766Black Pattern Imitation Leather 
768Medium Fawn Redmond Cloth, Medium Fawn Imitation leather 
769Medium Fawn Rio Cloth, Medium Fawn Imitation Leather 
770Medium Fawn Pattern Imitation Leather 
775Medium Turquoise Roncina Cloth, Medium Turquoise Imitation Leather 
776Medium Turquoise Imitation Leather 
778Medium Turquoise Imitation Leatherx
782Medium Gold Roncina Cloth, Medium Gold Imitation Leather 
783Medium Gold Imitation Leather 
784Medium Gold Imitation Leatherx
794Medium Gold Royale Cloth, Medium Gold Imitation Leather (sport sedan only)