Colour evolution is a tool to build parton shower and resummation algorithms, possibly beyond the large-N limit. In this talk I will outline how we can determine colour evolution equations for the hard scattering alongside those of a soft factor by appreciating the role of a perturbative infrared cutoff as a factorization scale. This analysis has a significant impact on how we understand and build hadronization models and corrections, ranging from the physics of colour reconnection to the dynamics at the "UV" scale of the hadronization process. It also instructs us to think differently of the way we assign comprehensive uncertainties to event generators, and how we interpret their parameters. Besides the theoretical framework I will show concrete steps and improvements in Herwig's cluster model building on this new paradigm, and the stepping stones towards a hadronization model for amplitude level parton showers.