Along with the change of a business comes the evolution of the company's logo. For example, the Shell petrol station to change in 1900.
The logo was a mussel shell to start with and then in 1904 it changed to a scallop shell,
giving a visual element to the brand name and corporate. Between the years 1904 and 1995 the shell become more and more graphic.
In the year 1999 the title of the station disappeared and just the shell remains and still to this day stays the same. The red and yellow colours appeared with the construction of the shell's first service station in California. Not only did the red and yellow help shell stand out, but they're also the colours of Spain, where many early Californian settlers were born. Perhaps by displaying spanish colours it was hoped that an emotional bond would be created.
An alternative idea about the shell's colours was that Mr Graham, the scottish director, suggested using red and yellow as they form the basis of The Royal Standard of Scotland.
In the days before fax machines and the internet, many logos included subtle details that would become blurred at small sizes. From the 1950's, the icons became more and more specified, improving recognition and memorability.
3. http://www.shell.com.sg/home/content/sgp/aboutshell/who_we_are/history/ history_logo/