Health monitoring cat litter color chart: what each color means
On most health monitoring litters, the base color — yellow-to-olive on crystals, beige on TellTail — means urine pH is in the normal range, orange means acidic, and blue or green means alkaline. Red usually means blood on crystal litters, but on TellTail deep red means strongly acidic urine, so always read the chart for your brand.
Updated 2026-10-11
Quick chart
| Color you see | What it usually means | Which litters use it |
|---|---|---|
| Yellow, olive green or beige | Urine pH in the normal range | PrettyLitter and Tidy Care Alert (yellow to olive green); TellTail (natural beige) |
| Orange | Acidic urine | PrettyLitter, Tidy Care Alert, Fresh Step, TellTail |
| Blue or dark green | Alkaline urine | PrettyLitter (blue), Tidy Care Alert (blue or dark green), Fresh Step (green or blue) |
| Soft green to deep green | Alkaline urine | TellTail |
| Red | Blood in the urine on crystal litters; strongly acidic urine on TellTail | PrettyLitter and Tidy Care Alert (blood); TellTail (pH around 4) |
Colors are not standardized across brands. The same shade can mean different things, so use the chart printed on your own bag.
Brand by brand
PrettyLitter
According to PrettyLitter's help center, dark yellow or olive green is the typical healthy range, orange signals high acidity, blue signals high alkalinity, and red signals blood. Source
Purina Tidy Cats Tidy Care Alert
Purina describes yellow to olive green as the normal baseline, deep yellow or orange as acidic, blue or dark green as alkaline, and red as blood. It also notes that a shift toward blue or dark green within an hour or two after eating is expected. Source
Fresh Step Clumping Health Monitoring
Fresh Step uses clay litter plus indicator granules you sprinkle on top. Its page links green or blue to alkaline urine and orange to acidic urine, and also links blue to possible blood, so check the brand's own guide for its granules. Source
TellTail
TellTail reads urine pH only. It has no blood indicator.
| Urine pH | Color | What to do |
|---|---|---|
| About 4 | Deep red | Strongly acidic. Call your vet this week — sooner if your cat is off food, vomiting, hiding or lethargic |
| About 5 | Orange | Acidic. Check whether your cat eats a urinary diet, add water to the routine, and book a urinalysis if orange keeps coming back |
| About 6–7 | Natural beige | Normal range. Nothing to do |
| About 8 | Soft green | Alkaline. Re-check a fresh morning clump before breakfast; if it stays green for several days, book a urinalysis with culture |
| About 9 | Deep green | Strongly alkaline. Confirm with a clump scooped within an hour or two; if it's still deep green, call your vet |
TellTail stays beige across the normal middle and only starts to shift below about pH 5.3 or above about 7.7.
Red on TellTail is not a blood test. If you've used crystal litters before, this is the one difference to remember.
How to read any color correctly
- Read a fresh clump. Urine drifts alkaline as it sits, so an old clump can overstate the reading.
- Morning is best. Urine runs more alkaline for a few hours after a big meal. A fresh morning clump before breakfast is the honest reading.
- Look for a pattern. One off-color clump is rarely meaningful. The same color several days in a row is worth a vet visit.
- Multi-cat homes: you won't always know whose clump it is. Separating cats for a day is the simple way to find out.
- Some causes have nothing to do with color. A cat straining in the box and producing little or no urine — especially a male cat — needs a vet the same day.
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Sources
Related
TellTail is a cat litter, not a medical or diagnostic device, and does not diagnose any condition. A color change shows your cat’s urine pH has shifted — an early reason to keep watch and check with your vet.