1. Installing the App
To install a ColourWorker app, go to the app's page and tap the download icon.
2. Logging In
When you open the app for the first time, you will be asked to sign in. You can use either your Google or Facebook account.
3. Selecting Your Subject Material
ColourWorker needs to know what kind of material you are measuring. This is because it uses spectral reflectance data (how light reflects off your material) to give accurate results.
The first time you open the app, you will be asked to choose:
- An application area (e.g., Conservation, Farming), and
- Your specific subject material (e.g., Blue-wool, Pears Forelle).
You can change these choices later:
- On iOS: Tap the ← (left arrow) in the top-left corner to go back.
- On Android: Use the back button on your phone.
- Or, tap the three dots (⋯) in the top-right corner and choose the option to change your material.
Note: We currently support a limited number of materials, but we are adding more regularly.
If you need a material that isn't listed—or if you have your own reflectance data you'd like to use—please contact us at: john@jackdawconsulting.co.uk
4. Making a Measurement
Once your material is selected:
- Tap the green arrow button near the bottom of the screen.
- The app will switch to camera mode.
- Place your ColourWorker colour standard (a small card with a hole in the center) on the surface you want to measure:
- Put the aperture (the small hole) over the exact spot you want to measure.
- Press the standard flat against the surface.
- Hold your phone so the camera is directly above the standard (at a 90° angle) to avoid glare or reflections.
- Center the colour standard both horizontally and vertically on your screen for best results.
- The app will automatically detected the colour standard and the shutter button will turn green. You can now take a photograph.
- Take the photo by pressing the shutter button.
Don't have a colour standard? You can order one [here].
5. Zoom Mode (Optional)
If shadows or reflections from your hand, clothes, or phone are getting in the way:
- Tap the three dots (⋯) in the top-right corner and select Zoom Mode.
- In Zoom Mode, fill as much of the screen as possible with the colour standard for the best accuracy.
6. Viewing Results
After the measurement, you'll see:
Top graph:
- Black line: The predicted reflectance spectrum of your sample.
- Grey lines: Reference spectra for your selected material type.
Colour section:
- Left: The part of the image used for the measurement (sampled pixels).
- Right: The average colour and its L*, a*, b* values (standard colour coordinates).
Comment field:
- Type a label (e.g., "Experiment 1, sample 2") and press Enter to save it with your measurement.
Accept/Reject toggle:
- Mark the measurement as Accepted (good quality) or Rejected (poor quality). This helps you filter results later.
Share button (bottom of screen):
- Tapping it opens your phone's normal sharing options (email, Messages, Dropbox, etc.).
- If you share by email, the subject will be: "Spectral reflectance at [date and time]"
- The email will include:
- GPS location (if you allowed location access),
- The reference material used,
- L*, a*, b* values,
- A CSV file of the full reflectance spectrum (easy to open in Excel, MATLAB, or similar programs).
View Measurement Details:
- From the three dots (⋯) menu, choose this option to open the web app with more detailed sample information.
7. Working Offline
ColourWorker processes data in the cloud, so you normally need an internet connection to see results right away.
However:
- If you start the app while online, it can save measurements offline and send them later.
- When offline, a small number in the top-left corner shows how many measurements are waiting to upload.
- Once you reconnect to the internet, these will be processed automatically.
- You can still view or share these results using the web app (see below).
8. Browsing Your Measurements Online
All your measurements are securely stored in the cloud (on Amazon AWS).
To view them:
- Go to the web apps page and log in with the same account you used in the mobile app.
- You can search by date.
- For full details about what data we store and how to delete it, please read our Privacy Policy.