Move the sliders, or type a hex code, to see which variant of the logo to use on that background.
For SOT a background answers two questions. The brand book allows the logo on the eight key colours “without changing its colour or any of its components” (p6, p9) — so this names the key colour to ink the mark in, and tells you whether your background is a recommended ground at all.
One file, no dependencies. Click the canvas or the filename to download that variant as an SVG — it is generated here in the browser, so this works offline.
Hue, saturation, brightness.
All eight key colours against the current ground.
| Ink | Hex | Contrast | Book | Verdict |
|---|
| Check | Source | Rule |
|---|---|---|
| Is the ground approved? | p6, p9 | The logo may be placed on a recommended background colour without changing its colour or components. That set is the eight key colours (p16, p44). Anything else is flagged off-palette, with the nearest key colour offered. |
| Is it a documented pairing? | p60 | The six ordered pairs of RGB Blue, RGB Green and RGB Magenta are shown in use in the brand book. These sort first and are labelled, even when contrast is low. |
| Does it hold up? | Derived | WCAG 2.2 1.4.11 non-text contrast: 3:1 minimum for a graphical object, 4.5:1 treated as strong. Plus a hue-vibration flag when two saturated hues sit within 90° at similar lightness. Not in the brand book. |
A documented pairing wins only if it also clears 3:1. So on a magenta ground this recommends black at 6.70:1, and explains that the p60 pairings (blue 2.74:1, green 2.29:1) belong to key-visual artwork at display scale rather than to the logo. A plain contrast checker would have called the brand wrong; a plain brand lookup would have handed you an illegible mark.