Lightening or darkening a colour by changing lightness alone (rather than also drifting its saturation or hue) is the most reliable way to get a paler or deeper version that still reads as 'the same colour' — this is the tint/shade relationship described in the glossary.
Practical advice
Adjust My Colour's 'lighter' and 'darker' options change lightness specifically, at three strengths, so the family relationship to the original colour stays recognisable.
| White added | As light | Hue | Towards white in OKLab | Hue |
|---|---|---|---|---|
| None | #0047AB | 260° | #0047AB | 260° |
| 25% | #8994C5 | 274° | #4877C3 | 260° |
| 50% | #BCC1DA | 277° | #83A4D9 | 260° |
| 75% | #E1E3EE | 278° | #C0D1ED | 260° |
Adding white as light turns the blue's hue from 260° to 277° at an even mix — 17° towards violet, the faintly lilac cast that screen tints of a strong blue often have. Moving towards white in OKLab holds the hue at 260°, so the tint still reads as the same blue.
How this was calculated. 'As light' is a weighted average with white in linear light, which is also what blending towards white in most software does. The OKLab column is a straight line from the colour to white in OKLab, a space built so that such a line holds hue. Hue is the OKLCH hue angle of each result.