Cadbury is an established chocolate company founded in 1824.
I believe the colour choice of this logo has had a huge impact on how people visualise the standard chocolate bar and one of the most well known chocolate companies that create world class chocolate.
The floating appearence of the logo conveys a dream like state. This suggests the chocolate is heavenly convincing the potential customers that Cadbury is a good choice!
Also the curved writing style shows fluidity suggesting the chocolate is well made but also that the company is adaptable to what its customers want.