they are good to use if: you swim a lot, use a lot of products, sweat/produce extra oils, work in polluted environments, or have well-water or other plumbing issues. if you are planning on using only demi/semi-permanent colors and want a 'fresh slate', you could use a clarifying shampoo..because those types only deposit, and its good to dispose of any barrier (oils, chemicals, etc) that would keep the demi/semi from staining well.
i'd be weary of suggesting a color formula/plan for you without being able to see your hair. my idea of brunette and blond highlights is probably different that yours. if you have little grey, or its only in a few areas that concern you, i'd suggest going with partial coloring/highlighting (whatever colors you choose is up to you), rather than all-over coloring. its less commitment, less time-consuming, and less costly.
at 8:56 PM on Jul. 16, 2012