Idents
Productions companies have ident's which are used to distinguish between different production companies. Idents are changed over they year. This could be due to better animation and graphics technology. There are big idents such as Disney and Warner Bros and small idents such as split moon films or ravenwood productions. Idents is a small animation at the start of the film to represent the production company
Warner Bros was founded in 1923; around this time there was no colour in film. Warner never decided to change their ident majorly. This way recognition is maintained. When colour is introduced thats when they added the colour in film. They also did not have a major change in colour over the years.
These are some more idents from different companies :