Towards consistent SCADA mimic colour practices

Abstract

This thesis investigates colour practices in SCADA mimic displays across the energy and marine industries, motivated by the observation that there is no universal standard governing how colours should be used in these systems. Three relevant standards were examined: ISO 14726 for piping identification colours, ISA-101.01 for human machine interface design principles, and WCAG2ICT for accessibility in non-web software. The alignment between these standards is partial and observed industry practices fill the remaining gaps inconsistently through vendor guidelines and organisational conventions.

Based on the reviewed standards and literature, 12 colour design guidelines were created. Three prototypes per industry were then designed: one with the current colour scheme, one closely following the guidelines, and one as a compromise between the two. The prototypes were tested with 10 industry professionals from Wärtsilä through think-aloud tasks, an interview, and a post-session survey.

The results showed a clear divide between Wärtsilä's industry domains. Full guideline alignment improved perceived usability for marine participants but reduced it for energy participants whilst the compromise prototype was broadly acceptable across both groups. Familiarity with existing colour conventions was a strong influential factor, especially in the energy group. These findings suggest that consistent SCADA colour practices should be pursued through shared principles adapted to industry-specific needs rather than through a single universal colour scheme.