TL;DR

In our previous post, we provided a comparable heuristic example using fill color in Google Draw application. This post extends testing ideas for color in that program. This post is aligned with the Black Box Software Testing Foundations course (BBST) designed by Rebecca Fiedler, Cem Kaner, and James Bach.

What do we know about color?

Color (American English), or color (Commonwealth English), is the characteristic of human visual perception described through color categories, with names such as red, orange, yellow, green, blue, or purple. This perception of color derives from the stimulation of cone cells in the human eye by electromagnetic radiation in the visible spectrum. Color categories and physical specifications of color are associated with objects through the wavelength of the light that is reflected from them. This reflection is governed by the object’s physical properties such as light absorption, emission spectra, etc. [Color – Wikipedia. https://en.wikipedia.org/wiki/Color].

The color needs our eyes to be able to manifest itself. This is why programmatically test the color is error-prone. How to check the fill color in professional drawing applications such as adobe photoshop? What heuristics could be used to generate testing ideas?

Here are some heuristics:

• use every color

But what is the total number of colors? On the web, you can find a different result. Monitors can display 16 million of them. You see the problem.

• the sample number of colors

Reduce the number of colors that can be viewed by the monitor. One possible list is a shortlist from Wikipedia.

• Fill different shapes

Which shapes do we test? Polyline, circle, rectangle, arrows. Again, we need to sample.

• Change platform

Change the operating system, graphics card, and screen resolution. How that affects color perception?

• Change display

Screen display versus a printed color page.

Who is the application user?

Artist, web developer or novice user that learns about colors.

Conclusion

Testing is about ideas. Heuristics give you ideas.