By this time period, the now-iconic yellow-and-red shell design began to materialize. The colors used on the logo are thought to relate to those of the flag of Spain, as Shell built early service stations in California, previously a Spanish colony.
The shell design was modified to its current form in 1971; this logo was created by Raymond Loewy.
The wordmark typeface was changed in 1995. It's still used on some gas stations.