Part 2 of 3
Fabric and color guide
Once you understand the chemistry, the risk hierarchy makes intuitive sense. Two things determine how quickly damage shows up: how readily the fiber absorbs liquid, and how stable the dye is under oxidation. Synthetic fabrics score well on both; cotton and linen score poorly on both.
Simulated bleach swatches
Visual simulations of typical real-world discoloration patterns. Actual results vary by formulation strength, BP concentration, contact time, wash chemistry, and dye lot.
Cotton · Navy
Before
After
Azo blue dye oxidizes to a rust-orange. The characteristic BP damage color — distinctly warm, not brown.
Cotton · Black
Before
After
Similar chemistry to navy; the warm rust-orange patches are extremely visible against the original black.
Cotton · Forest green
Before
After
Green is typically a mix of blue and yellow reactive dyes. The blue component fades first, leaving a dull yellow-olive tone.
Cotton · Red
Before
After
Fades to a washed-out peachy pink. Patches are often blotchy rather than even.
Cotton · Sky blue
Before
After
Light reactive dyes have little pigment depth — bleaches to near-white with almost no residual hue.
Polyester · Navy
Before
After
Disperse dyes are more oxidation-stable. Color fades and washes out rather than shifting to a different hue.
Lyocell · Yellow
Before
After
Light-toned dyes fade gradually rather than shifting hue. Visual change is subtle and often unnoticeable.
Cotton · White
Before
After
Oxidation occurs but there is no meaningful contrast change. White is genuinely one of the safer choices.
Fabric risk comparison
Ordered from most to least resistant.
| Fabric | Risk | Why | Practical note |
|---|---|---|---|
| Polyester | Low | Hydrophobic fibers reject water-based liquids; disperse dyes are significantly more stable against oxidation than reactive dyes. | The safest option for dark colors. Even saturated polyester holds up reasonably well over time. |
| Nylon | Low | Also synthetic and hydrophobic; uses disperse or acid dyes with similar oxidation resistance to polyester. | Good for athletic wear and compression garments. Check blend composition on labels. |
| Acrylic | Low to medium | Synthetic fiber with generally stable dye chemistry, though quality varies significantly by manufacturer. | Less common in bedding. Fine for knitwear that has limited skin contact. |
| Wool | Low to medium | Protein fiber dyed with acid or metal-complex dyes, which are more oxidation-stable than reactive dyes. Naturally water-repellent lanolin also slows absorption. | Generally more resistant than cotton, but merino and fine-knit wool items sit close to skin — watch necklines and sleepwear. |
| Silk | Medium | Protein fiber with moderate dye stability, better than cellulose but thinner and more delicate than wool. | Technically more resistant than cotton, but too expensive to risk on pillowcases or items with nightly contact. |
| Lyocell / Tencel | Medium | Cellulose-based but processed to a smoother, more uniform fiber structure with a lighter dye load than standard cotton. | Safer than cotton in pastels and neutrals. Still avoid deep saturated colors for pillowcases and towels. |
| Modal | Medium | Higher-quality viscose process yields more uniform dye distribution, but it is still a regenerated cellulose fiber. | Better than basic rayon, not as safe as polyester. Avoid deep colors for any high-contact item. |
| Cotton | High | Cellulose fibers readily absorb BP; reactive dyes — the standard for cotton — are highly vulnerable to oxidative breakdown. | White, off-white, and very light shades are fine. Anything dark or saturated will visibly bleach with regular exposure. |
| Linen | High | Same cellulose fiber and reactive dye vulnerabilities as cotton. Heavier weave does not meaningfully slow BP penetration. | Best in undyed, white, or natural tones. Often sold in safer neutrals by default. |
| Rayon / Viscose | High | Regenerated cellulose absorbs liquids readily and often has uneven fiber structure, leading to blotchy rather than gradual fading. | Treat as high risk across all saturated colors. Among the worst-performing fabrics for BP resistance. |
| Bamboo fabric | High | Despite the branding, almost all bamboo fabric is processed into viscose. It carries the same vulnerabilities as rayon. | "Bamboo" does not mean resistant. Check the fiber content label — it almost always reads "bamboo viscose." |
Color risk comparison
Risk assumes a cellulose fabric (cotton/linen). On polyester, all colors are lower risk. Ordered from highest to lowest risk.
| Color | Risk | What typically happens |
|---|---|---|
| Black | High | Orange or rust-colored patches. The highest visual contrast of any color — even small spots are hard to miss. |
| Navy / deep blue | High | Rust-orange shift. Characteristic and unmistakable. One of the most commonly reported BP damage patterns. |
| Forest / olive green | High | Dull yellow-olive or mustard tone as the blue dye component fades before the yellow. |
| Deep red / burgundy | High | Fades to a dull, blotchy peach-pink. Burgundy tends to look particularly washed-out. |
| Magenta / hot pink | High | Shifts toward pale, washed-out peach. Saturated warm tones fade rapidly. |
| Sky blue / baby blue | Medium–high | Bleaches toward near-white with minimal hue shift. Less "orange," more just gone. |
| Mid gray / heather | Medium | Gradual, diffuse fading. Less dramatic than dark solids, but still visible on lighter heather over time. |
| Light pink | Low to medium | Subtle fading. Small patches can be hard to distinguish from normal wear. |
| Ivory / cream | Low | Minimal visible change. Slight brightening at most. |
| White | Low | Oxidation occurs but produces no visible contrast. The safest color choice on any fabric. |
| Oat / sand / pale yellow | Low | Very subtle, often unnoticeable brightening or shift. Light warm tones hide color change well. |
A note on blends
Blended fabrics don't follow a simple average of their components. A 60/40 cotton-polyester pillowcase may bleach almost as badly as 100% cotton if the cotton component absorbs the bulk of the BP and the reactive dye is used for the full color range. The polyester component doesn't “protect” the cotton fibers from oxidation — it just means fewer cotton fibers are present.
Performance-blend athletic fabrics (often 90%+ polyester) tend to behave more like pure polyester and are generally safe. Low-cost cotton-poly blends for bedding behave more like cotton in practice. If you're testing a blend, check one item for a few weeks before committing to a full set.