The computer screen photoassisted technique (CSPT) uses displays as controlled light sources for measuring spectral fingerprints of color substances, such as those present in bioassays. Here, the possibility of tuning the illuminating sequences for matching CSPT fingerprints with target spectral transmittances is demonstrated. This approach enables robust classification; orders of magnitude form mismatches, and establish a systematic method for adapting optimum illuminating sequences to any unknown measuring platform.