There is a great post at The Online Photographer: Everything’s Relative

Often it’s if your goal is to make something look brighter (or darker), it’s better to alter the context than it is to adjust the absolute brightness of that spot in the print.

He uses a photo for his example, but the idea works in general graphic design as well. Making a change in the way something is seen isn’t always about altering the subject. Often it’s the context. How many times has a client asked you to “Bold everything, It’s all important!” It’s all about context. When everything is bold, nothing is bold. Change the context that the text is seen in, and you can change the way it’s seen, draw attention to where it should be.