In the outer solar system beyond Neptune, there exists a region populated by small icy bodies known as Trans-Neptunian Objects (TNOs). These objects are remnants of failed planet formation, offering a glimpse into the early solar system due to their distance from the Sun, which has shielded them from significant disturbance since their formation during the period of giant planet migration. The Colours of the Outer Solar System Origins Survey (Col-OSSOS) measured the optical/NIR colours of a brightness complete sample of TNOs. Like previous surveys this revealed a bimodal colour distribution, made up of red and very red TNOs. Additionally, an analysis of these colours in relation to the solar reddening line has led to the identification of surface classifications termed FaintIR and BrightIR where like the names imply, BrightIR are relatively brighter at IR wavelengths and FaintIR are relatively fainter. Cold classical TNOs mostly exhibit very red or FaintIR surfaces, while dynamically excited TNOs demonstrate a mix of surface types. This differentiation likely corresponds to a potential connection between the formation locations of TNOs and their subsequent surface characteristics, with proximity to the Sun at their formation time potentially leading to surface volatiles loss and colour alteration. Our study combines the data from Col-OSSOS with two dynamical models describing the formation of the Kuiper belt during Neptune's migration. We investigate the proposed surface-colour changing line and explore the distribution of different surfaces within the primordial disk. By comparing radial colour transitions across various scenarios, we explore the origins of surface characteristics and their implications within the context of BrightIR and FaintIR classifications. Moreover, we extend our analysis to examine the distribution of these surface classes within the present-day Kuiper Belt, providing insights into the configuration of the early solar system's planetesimal disk prior to giant planet migration. We will present the results of these simulations, and compare with other studies and observations to show that the most likely primorsial disk compositions are inner red / outer very red (with transition ), or inner BrightIR / outer FaintIR (with transition ).