Screen colour vs thread colour: why they don't match
You open a chart on your tablet, look at a swatch in the key, and the skein with the same number in your hand looks different: darker, warmer, duller. The chart isn't wrong and the thread isn't faulty. A screen and a thread show colour in different ways, so they can never match exactly.
A screen glows, a thread reflects
A screen gives off its own light: every dot is a mix of red, green and blue. A thread has no light of its own. It reflects part of the light that falls on it. So the colour of a thread depends on the lamp in your room, and the colour on a screen depends on the screen's settings.
What changes colour on a screen
- Brightness and automatic settings. Night mode and adapting to room light make the picture warmer to rest your eyes. Swatches shift along with the whole screen.
- The screen itself. Different phones and tablets show the same colour a little differently.
- The background. On a dark theme the same swatch looks lighter and brighter than on a light one. Your eye judges a colour against its neighbours.
- Where the swatch comes from. The colour in a chart key is an approximation chosen by the designer or the charting program. It hints at the thread; it doesn't replace it.
What changes colour in a thread
- Light. A warm lamp in the evening and daylight by a window give the same thread different tints.
- Sheen and twist. Stranded cotton has a sheen, and one leg of a cross can look lighter than the other.
- Strands and fabric. One strand lets the fabric show through; two strands nearly cover it. Dark or coloured fabric noticeably changes how light threads look.
- Neighbours. In a finished piece each colour sits next to others, and that changes the impression more than you'd expect from the skein.
How to choose threads without mistakes
- Go by the number, not the swatch. The thread number in the key is what matters. The swatch on screen helps you find the symbol quickly, but you choose by code.
- Compare in daylight. If you're torn between two skeins, compare them by a window during the day, not under an evening lamp.
- Keep a physical colour card. A manufacturer's card with real thread is more reliable than any screen. If you don't have one, make your own: short lengths of thread with their numbers written next to them.
- Test on the fabric. Before a large area, stitch a couple of crosses at the edge of the fabric and see how the colour sits on it.
- Find substitutes by code, not by eye. If you don't have a thread, use conversion charts or a colour card to find a replacement, not the screen.
Where the app fits
In Crossette a chart keeps the thread numbers from an OXS file with thread codes. You can highlight one thread across the whole chart, see how many stitches of it are left, and check it against your thread stash and shopping list. The colour on screen stays a hint; choose the thread by its number. For working from a chart on a tablet, see "Stitching from a digital chart", and for how the key works, see "How to read a chart".