Color-based reaction testing of biological materials may be performed by capturing, in an uncalibrated environment, a digital image of an exposed test strip, together with an adjacently-located reference color chart or on-strip color chart. The image data specifically representing the individual test pads on the test strip, as well as the reference color blocks on the reference chart, are then located within the captured image, and compared to identify any color matches between the test pads and the corresponding sequences of reference color block. Based on this comparison operation, a set of test results can be generated which effectively identifies which of the reference chart's color blocks most closely matches the color of the corresponding dipstick's test pads. The generated test results may then be provided to the user in a printed or displayed form. Alternatively, the test results may simply be stored for later retrieval.