So I have a website that consists of 15 major modules or lack of a better term sections. Each of these consist of very different objectives. One presents news the other shows you a job listing and ext. I was thinking color coding each of these sections and giving them unique icons to help the user navigate easier by association. I'm just wondering is this a bad idea because of there being so many sections. This would require me to insert 15 different colors. Right now I'm using just 6 colors and proliferating them to all 15 major sections so this means replicating the same color for different sections. The problem I have with that is that its not tying each section to a different color which might confuse the user. What should I do? Inside this picture I have a rough mock up at the top and my swatch configuration at the bottom.
The best rule of thumb is to never encode necessary information with color alone. So if these 15 swatches are the only way to find each segment in the layout or to tell which segment an article belongs to, you're going to have some usability issues.
Beyond that the biggest risk is if you have color coding associated with other considerations, like the brand identity or success/failure, etc. Colors too close to these could be confusing. This also holds for if any of your 15 swatches are difficult to distinguish. That number feels large to begin with.
Have you considered logical groupings? It seems like marketplace, classifieds, homes for sales, apartments for rent etc. all have a lot more in common than say, jobs and videos, yet the latter pair is closer in color. Thematic linking can give you wiggle room for colors which are closer together, or even reused. On the other hand, accidental linking between disparate segments could create confusion.
Finally, maintainability is something to consider. 15 swatches is a lot for implementation to keep track of reliably. If you want to change them, it could be a chore to hunt down, even with modern precompilers. Your programmers are also users of your design, in an abstract way. But these considerations are minor compared to the others.
I used multiple discussion and answers to figure out what should happen. So going along with Nathans suggestion "read comment above". I'm going to group related sections with a dominate color like red, green, blue, ext. Then each one of those sections inside that dominate color will have variations of that color chosen. Ex: News, Blogs will be two different types of blue. Not only I'm going to color by grouping but also use icons to give each section a unique attribute to further distinguish them from each other.