Color is a finicky thing. Due to the large number of color spaces and color profiles in use today, color needs to be defined with care.
Your Cube Companion App and Cube Link App provide a range of raw color data, expressed in different color spaces and profiles. You may find that you are not receiving the results
Your RGB data does not match the actual values
There are a couple of reasons why this may happen:
- The actual RGB values (such as those provided on swatches or samples) will likely be specified differently. They may be specified using a different RGB profile, or a completely customised RGB space - common amongst paint brands.
- Non-linearities in the RGB space. Sometimes, two colors which are visually indistinguishable may have RGB values which appear significantly different. This is due to inherent non-linearities within the RGB space.
For the above reasons, it is generally better to compare colors using LAB data which is less dependent on specific color profiles.
Your LAB data does not match the actual values
The best way to compare two colors is by using their LAB values. Unfortunately, even this method has a number of drawbacks:
- Differences in illuminant standard. Color measurement depends heavily on the color of the illuminant used to light up the surface. Cube uses an internally controlled light source designed to match D50 illumination. Other color measurement devices or color standards may use other illuminants.
- Differences in sampling interface geometry. Cube uses a spherical geometry which differs from 45/0 degree geometry used in some spectrophotometers.
You are scanning a surface which is hard to measure
Cube uses an internal light source and detector to read color, and this means some surfaces can't be captured very well.
For example, Cube doesn't perform optimally on surfaces which contain fluorescent inks (common in certain fabrics, post-it notes etc).
For a more comprehensive list of surfaces to avoid click here.
You have hit the limits of Cube
As with all measurement instruments, Cube is not 100% accurate and is subject to internal errors which can have an effect on measurements. You may be interested in Cube's technical specifications.