I appreciate what you're trying to do, Jonesy, but I suggest you don't try to choose colours by photos found online, there are too many variables.
Different lighting, camera settings, and even computer monitors/displays can all change the hue slightly, plus different coloured undercoats change the colour too if the coverage isn't 100%, then something else like a pearl or a mica may have been added to the mix, and modern paints don't contain lead like those from the '70s.
Problem with all that is, you might pick a colour from a photo and then discover that it's not what you expected after buying the paint? You are far better off going to as many car shows as you can find and looking at colours in person, talking with the owners, and so on.