The production of striped catfish, Pangasianodon hypophthalmus, is amongst the largest aquaculture industries in Southeast Asia. Over 1.2 million tonnes per year are produced by aquaculture in Vietnam alone, with most production going to processed fillet export markets, including Europe, the USA and Australia. Consistent fillet quality is important and has a significant influence on farm-gate prices achieved by producers. For instance, undesirable fillet colour can reduce the farm-gate price by over 50% of its typical value. The most desirable colour for Vietnamese catfish fillets is white, although it is common to observe fillets with pinkish or yellowish tones. If fillet colour is under genetic control, it is possible to improve through selective breeding. This study has two main aims: 1) to develop an objective, rapid methodology for measuring fillet colour in P. hypophthalmus, and 2) use such measurements to estimate the genetic parameters (heritability, genetic correlations) in a commercial breeding population of P. hypophthalmus. To achieve this, digital images were taken of 5864 individual fillets, comprising 328 families over 4 spawning cycles. Each image was decomposed into different channels of the Red-Green-Blue (RGB) and LAB colour spaces and the average channel value was estimated for each fillet. Using the various channel values as phenotypes, heritabilities ranged from 0.18 ± 0.03 – 0.47 ± 0.04 for the RGB colour space and 0.19 ± 0.03 – 0.62 ± 0.04 for the LAB colour space. These preliminary results indicate genetic variation exists for fillet colour in P. hypophthalmus and therefore has potential to be improved by selection in ongoing breeding programs. Interpretation of digital image colour space channels in relation to the application for breeding for fillet colour is discussed. We also consider potential strategies for incorporating such an approach into routine genetic evaluation.