This is attaching meaning to a subject by using another side by side. A picture by itself may have no significant meaning; however adding a caption will give it a meaning. This is most often seen in adverts and odd pictures on Facebook.
‘Doctor Who’ is much more colourful nowadays than it used to be. Obviously when it first started off it was in black and white but even when it went into colour in the 70’s, 80’s and 90’s, it still wasn’t as colourful as it is now. Also the fonts used are a lot more prominent and bold on screen and they stand out more, not just in the title sequence, but in recent episodes it has even given the year and the location away at the start of the episode in the form of bold text. Obviously in the title sequence the font is much larger and centered as that information is more important than the year and location information, which is small and at the side of the screen. In the title sequence you don’t just have the ‘Doctor Who’ logo, but also the name of the episode and the name of the writer after the ‘Doctor Who’ logo has been displayed, and the actresses and actors names before the ‘Doctor Who’ logo is displayed. Target audience comes into it too, as when ‘Doctor Who’ first started it was quite moody, dark and mysterious whereas nowadays it’s more cheerful and it has more comedy elements, and the colours and font being different in the program over the years were used to reflect this.