If you are
– working on presales
– working on concept design
– working on ideas to share with customer
– working on some proposal
any scenarios, where you need to bring branding part, theming, customization of look and feel.. You can use www.kuler.adobe.com app, its free to use web based solution from ADOBE. There are some other applications, but Kuler is one of the best.
Subject based Search – This has great search engine, where we can write our subject and it gives exceptional result with great color palette. Your subject can be – company name, emotion, business (hospitality, finance, govt, sports) .. .etc