PBN in hair color means Permanent Brown Neutral. It's part of the numbering and lettering system professional colorists use to categorize hair dye shades. The P indicates permanent color (as opposed to semi-permanent or demi-permanent), B means brown, and N signals a neutral tone that doesn't lean warm (golden, red) or cool (ashy, violet). This coding system helps stylists match existing hair color, mix custom shades, and communicate precisely with clients and other professionals. Different manufacturers use slightly different codes, but the pattern stays consistent across brands like Wella, Redken, and L'Oréal Professional. If you arrived here searching for PBN in an SEO or link building context, you're likely looking for Private Blog Network instead. A PBN in SEO refers to a group of websites created specifically to build backlinks to a main site, attempting to manipulate search rankings. Google explicitly prohibits this practice in its guidelines and actively penalizes sites caught using PBNs. The risk includes manual penalties, algorithmic devaluation, and complete deindexing from search results. At Ottawa SEO Inc., we manage a 500+ domain portfolio, but these are legitimate businesses and content properties, not a PBN. Each site serves real users, generates organic traffic, and operates independently. The difference matters: a PBN exists solely to pass link equity and typically features thin content, expired domains with manufactured histories, and footprints like shared hosting or WHOIS details. A legitimate portfolio consists of sites with genuine audiences, diverse monetization, and content created for users first. If you're researching hair color codes for a beauty industry client's content strategy, understanding professional terminology like PBN helps you create authoritative resource pages that rank for stylist and consumer searches. If you meant the SEO term, avoid PBNs entirely and focus on earning links through quality content, digital PR, and relationship building with real sites in your niche.