Colour matching system for colour approval of multi-component apparel

Abstract

This project is focused on the study of the existing colour approval procedure in Triumph in comparison with the procedures used by the vendors/suppliers in order to establish the improved lab dip and bulk samples colour approval procedures. The gap between visual colour assessment and digital colour was thus bridged to create a more precise colour standard for colour approval and minimise the discrepancy. As a result, the colour approval rate could be increased, thereby reducing the problem of delayed production and the adverse effect on the supply chain. A total of 120 batch samples with different materials, fabrications and colours plus their corresponding colour standards collected from the Triumph International Overseas Limited were used to prepare standard-batch sample pairs for visual and instrumental colour assessment. The 120 standard-batch sample pairs were visually assessed by 29 observers under D65 with two visual colour assessment methods. The sample pairs were also instrumentally measured by spectrophotometer using instrumental colour measurement methods. Paired t-test was used to analyse the significant differences between two visual colour assessment methods based on the percentage acceptance and the observer accuracy. It was also used to determine the significant differences between the colour difference values calculated by different colour difference equations and different instrumental colour measurement methods. The agreements between different visual and instrumental colour assessment methods were compared in terms of WD%. A proper tolerance block was then determined by having a small WD% between the visual and instrumental colour assessment results. Some case studies were also conducted to determine (1) how many readings should be obtained from the instrumental colour assessments for commercial uses; (2) the influence of sample conditioning on the instrumental colour measurement of nylon interlock fabric; and (3) the correlation between solid colours measured by spectrophotometer and DigiEye.