Understanding the Colors of Positive UTI Test Strip Results

Dinesh Patel
Medically reviewed by
Dr. Kaushal

Review medical content on WOW Rx Pharmacy, so that accurate drug use information is easily accessible to everybody.
Dr. Akansha is a licensed Clinical Pharmacologist. She possesses remarkable knowledge in Pharmacovigilance, prescription analysis, drug information, and drug safety services. Additionally, she is a keen learner and an educator.

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colors of positive UTI test strip results

Urinary Tract Infections (UTIs) can cause uncomfortable symptoms that prompt many individuals to seek medical attention. 

When these symptoms arise, healthcare professionals often recommend a urine test strip analysis to provide valuable insights into the possible presence of a UTI. 

This non-invasive test involves using specialized strips to assess various components in the urine. 

It helps to identify potential infections and other underlying health conditions. 

This article will look into the significance of colors of positive UTI test strip results.

Understanding positive UTI test strip result colors

Urine strip contains several pads or fields designed to detect specific substances in urine, like proteins, glucose, ketones, blood, and more. 

One crucial aspect of these tests is interpreting positive results, often indicated by distinct color changes when dipped in urine. 

There are many parameters urine strip measures: 


This color indicates the presence of Albumin in the urine.

  • Principle: The test for Albumin on UTI test strips is based on the “protein error” principle of indicators. At a buffered pH, Albumin reacts with a specific chemical on the strip
  • Positive result: If the strip changes color from yellow-green to green-blue, it indicates the presence of Albumin in the urine
  • Diagnosis: Albuminuria, or the presence of excess Albumin, may suggest kidney damage or other health issues
Albumin is the most abundant protein in blood plasma, constituting approximately 60% of the total protein content. It maintains the osmotic pressure of the blood, which is essential for regulating the distribution of fluids between the bloodstream and body tissues.

Gray-blue to orange

Change in color from Gray-blue to orange indicates ascorbic acid in the urineSource: Teka77_from_Getty_Images
Orange color strip

This change in color indicates ascorbic acid in the urine.

  • Principle: The test for ascorbic acid on these strips is based on the de-coloration of a chemical called Tillman’s reagent
  • Positive result: The color change from gray-blue to orange signifies the presence of ascorbic acid
  • Diagnosis: High ascorbic acid concentrations may be related to vitamin C therapy, medications, or dietary factors. It can affect the interpretation of other test fields

Pink to red-violet

This color changes indicates the there is high Bilirubin present in the urine.

  • Principle: The test for Bilirubin involves the coupling of Bilirubin with a diazonium salt
  • Positive Result: A change in color from pink to red-violet indicates the presence of Bilirubin in the urine
  • Diagnosis: The presence of Bilirubin in urine can be indicative of liver damage, Cirrohsis, gall bladder disease, and biliary obstructions (blockage in the bile ducts, which carries bile from the liver to the small intestine)
Biliary obstruction symptoms include severe abdominal pain, Jaundice, dark urine, pale stools, and itching. If the treatment is not proper or delayed, it can cause some serious complications.


If the color changes to green it means there is blood in the urine.

  • Principle: The test for blood on UTI test strips relies on the pseudo-peroxidative activity of Hemoglobin and Myoglobin
  • Positive result: The color changing to green suggests the presence of intact erythrocytes and, consequently, blood in the urine
  • Diagnosis: Hematuria, or blood in the urine, can result from various conditions, including infections, kidney stones, poisonings, and hemolytic anemias

Blue-green to yellow

This colour change compares the density and gravity of urine to water. 

  • Principle: The test estimates urine density based on color changes
  • Positive result: The color change from blue-green via green to yellow indicates the concentration of ions in the urine
  • Diagnosis: Urine density can provide information about kidney function and hydration status

Green to bluish-green

This colour changes detects the presence of glucose in the urine. 

  • Principle: The test for glucose is based on the glucose oxidase-peroxidase-chromogen reaction
  • Positive result: A change in color from green to bluish-green to dark brown suggests the presence of glucose in the urine
  • Diagnosis: Glucosuria, or glucose in the urine, can signify Diabetes or other metabolic disorders


If the urine strip changes to red or light red it means Ketone is present in the urine.

  • Principle: The test for ketones is based on Legal’s test, detecting Acetoacetic acid 
  • Positive result: A color change to red indicates the presence of ketones
  • Diagnosis: Ketones in urine can signal abnormal carbohydrate metabolism, often associated with conditions like Diabetes or starvation

Pale pink to red violet

This range of color indicates the presence of leukocytes in urine.

  • Principle: The test detects leukocytes based on their esterase activity
  • Positive result: A change in color to pale pink to red violet suggests the presence of leukocytes in the urine
  • Diagnosis: Leukocyturia may indicate infections of the kidneys or urinary tract

White to pink

The color detects the presence of Nitrite in the urine.

  • Principle: The test for nitrite detects microorganisms capable of reducing Nitrate to Nitrite
  • Positive result: A conversion from white to pink color indicates a bacterial infection in the urinary tract
  • Diagnosis: Nitrite-positive results suggest a urinary tract infection, typically caused by bacteria like E. coli

Red-orange to blue-green

Change in color from Red-orange to blue-green measures the pH level in urineSource: phototake_from_Getty_Images_Signature
Blue-green color strip

This change in color measures the pH level in urine. 

  • Principle: The pH test measures the acidity or alkalinity of urine
  • Positive result: The color scale provides information about the pH value. The color changes from red-orange to blue-green
  • Diagnosis: Abnormal pH levels can be associated with various health conditions


This color indicates urobilinogen in urine. 

  • Principle: The test detects urobilinogen by producing a reddish azo compound
  • Positive result: A change in color to reddish suggests the presence of urobilinogen
  • Diagnosis: Elevated urobilinogen levels may indicate liver dysfunction or hemolytic diseases
Recommended Article
To know about other urine tests than urine strips for UTIs, read Urine Test for UTI: An Essential Diagnostic Tool for Urinary Tract Health.


Understanding the colors of positive UTI test strip results helps experts identify potential issues, particularly concerning your urinary tract.

Each color change signifies the presence or absence of specific compounds in your urine, and interpreting these results can shed light on various aspects of your health. 

From kidney function and liver health to infections or metabolic disorders, UTI test strip colors are your body’s way of communicating its condition.

While they provide essential insights, they are not the sole basis for a final diagnosis. 

Further medical evaluations are often needed to confirm specific conditions and develop a tailored treatment plan.

It is recommended to consult a healthcare professional who can interpret the results with context to your medical history.

Frequently Asked Questions

What are UTI test strips, and how do they work?

UTI test strips are diagnostic tools used to assess the composition of a urine sample. Each strip typically contains several pads or fields designed to detect specific substances in urine, like proteins, glucose, ketones, blood, and more. These pads change color when the strip is dipped into a urine sample.

What do the different colors on a UTI test strip indicate?

The different colors on a UTI test strip represent the presence and concentration of specific substances. For example, a color change on the pH pad from orange to green might suggest altered acidity in the urine. In contrast, a color change from yellow to green indicates the presence of blood.

What are some potential health conditions associated with positive UTI test strip results?

Positive UTI test strip results can be associated with various health conditions, depending on the substance detected. For instance, glucose in the urine (Glucosuria) can indicate Diabetes or metabolic disorders, while blood in the urine (Hematuria) can result from infections, kidney stones, or Hemolytic anemias.

Can UTI test strips be used at home?

UTI test strips are designed for home use and are readily available over the counter at most pharmacies. They are user-friendly and come with clear instructions. However, if you have any concerns or questions it’s always a good idea to consult with a healthcare provider.

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