Brand guides from pre-web era often specify colors in Pantone (spot colors) or CMYK (process printing). Neither maps cleanly to the RGB color space that screens use. Converting between them is lossy, meaning some print colors simply cannot be reproduced on screen, and vice versa.
Why Conversion Is Not Exact
CMYK is a subtractive color model (ink absorbs light). RGB is an additive model (pixels emit light). The gamuts (range of producible colors) overlap but are not identical. Vivid oranges, deep purples, and bright greens in RGB often cannot be matched in CMYK. Conversely, some subtle earth tones achievable in print look different on screen.
Pantone to Hex
Pantone provides official hex equivalents for most of their colors, and these are the best starting point. However, "official" does not mean "identical." The hex value is Pantone's best approximation given the limitations of RGB. Always verify the result visually on a calibrated screen.
Practical Workflow
If you have print brand colors to bring into web: find or request the official hex equivalents from the brand guide. Import them into PaletteRx. Validate for web-specific needs (WCAG contrast, digital viewing conditions). Adjust if necessary, documenting the deviation from print values and the reason for it.
When Colors Must Differ
Sometimes a print brand color fails web accessibility requirements. A medium-saturation print color might not have sufficient contrast for web text. In these cases, you have two options: adjust the web version slightly (darker or more saturated) to pass contrast, or use the exact print color only for decorative elements and choose a modified version for text-adjacent uses.