Reading Q.E.D. by Richard Feynman, questions regarding speed of light at different colors I have very recently begun reading Q.E.D. by Richard Feynman (I have no physics background, only learning concepts not mathematical models). In his example of light reflecting off of glass, he mentions that the speed of the 'stopwatch' which runs for each photon moves at different speeds depending on the wavelength of a given photon. I was under the impression that all light moves at c regardless of color given its in a vacuum. My question is what is accounting for this change in speed of the 'stopwatch' of each photon (those of different colors)? I apologize if I have not worded this question appropriately, again I have no formal/mathematical physics background. Thank you. 
 A: The stopwatch idea  is to simplify the phase of a light wave, Feynman is describing the interference of light, and the visual effects of  the constructive or destructive interference. He is trying to avoid complex numbers and vectors as much as possible, while at the same time attempting to explain why, say oil films on water can reflect colors.
That is why he uses pictures such as : 

Image Source: QED Feynman.
The speed of light is constant, and your best approach is to keep reading on as later in the book it makes more sense.
Actually, if you have the courage :), it is really easier to learn this mathematically from any first year undergraduate physics book, than to try and follow analogies. In your local university bookshop, if it has a variety of textbooks, spend 30 mins looking through them and I think you will be surprised at the effort some authors and illustrators put into making an understanding of physics as painless as possible.
Looking online is good, if you trust the reviews. Halliday and Resnick is very straightforward.
A good more advanced resource regarding phases of waves is Wikipedia wave phases, but if you have the interest, and take the time, it will pay off.
A: By speed of the stopwatch, he meant the rate at which the hand of the clock moves - a faster clock, a slower clock.
You are rightfully confused to think that by speed he may have meant the literal speed of the clock, as in miles per hour. He didn't.
In his analogy of using stopwatches to explain reflection phenomenon, the rate of ticking of the stopwatch matters because for the same amount of time, the angle of rotation of the hand for two photons with differently sped up clocks would be different and so would be the resultant amplitude of the respective arrows upon adding.

Disjoint from above is the discussion about the speed of light. (Note that Feynman's discussion in the QED book doesn't bring up the speed of light at all.)
All light does move at the speed of, well, light in vacuum, regardless of their energy or intensity or color.
In materials though, the speed of light is different for different colors. Red is faster than blue but slower than in vacuum.
(Look up dispersion)
A: All the colors go the same speed in a vacuum, in a material like glass the different colors all have different speeds and that's why the colors breakup in a prism.
