This numerical system designates a specific shade range within professional hair coloring products. Generally, the first number (27) represents the primary hue, which in this case likely indicates a medium to dark blonde with violet undertones. The second number (30) typically signifies the secondary reflecting tone, often a golden blonde or warm brown. Combined, these numbers create a nuanced shade often described as a warm, golden, or strawberry blonde.
Utilizing a numbered system offers precision and consistency in achieving desired hair color results. This is particularly valuable for professionals, allowing for clear communication and replication across salons and stylists. The numerical system simplifies the selection process for a wide range of hair colors, moving beyond ambiguous descriptive names, and contributes to predictable outcomes. This standardization likely evolved with the development of complex chemical formulations in hair coloring, necessitating a more precise method of identification and communication.