How PRISMA effectively detects yellow yarn faults

If you want to see Yellow, you need Blue

Yellowing in yarn production is a subtle but stubborn problem that can ruin the purity and color accuracy of your final textile products. Whether it’s natural fibers or finished yarn, improper storage and transport — especially exposure to sunlight — cause oxidation that shifts the fiber’s natural color toward a pale, undesirable yellow. Even during weaving, the sizing process can introduce yellowing if chemicals or drying temperatures are too aggressive. Prisma is the only yarn clearer on the market which can map the color of the cleared events. Clearing of yellow contamination is another added value for the spinning mill.

PRISMA's unique blue light

Here’s why blue light makes all the difference:

For spinning mills aiming for pristine white or color-true yarns, detecting this yellow tint early is critical. Enter YarnMaster PRISMA, the only yarn clearing sensor on the market that uses a unique RGB measuring method to reliably spot yellowing — and it’s all about the blue light.

Yellow contains a high proportion of red light, which is why yellow tints vanish under red light.
Green light is mostly reflected by yellow, making the tint even harder to detect.
But blue light? Yellow and blue are complementary colors on the color wheel, meaning yellow absorbs blue light.

This absorption makes yellow discoloration stand out vividly under blue light, something no other yarn clearer can do. PRISMA’s innovative sensor shines red, green, and crucially, blue light on the yarn, isolating yellowing with unmatched accuracy.

The result? Consistent yarn quality, fewer defects, and confidence that your white or color-critical yarns meet the highest standards.

When it comes to detecting yellowing and yellow contamination in yarn, if you want to see yellow, you need blue. And that’s why modern spinning mills choose PRISMA — the only choice for flawless yarn quality.