  Type Ia supernova (SNIa) are excellent probes of local distance, and the
increasing sample sizes of SNIa have driven an increased need to study the
associated systematic uncertainties and improve the standardisation methods in
preparation for the next generation of cosmological surveys into the dark
energy equation-of-state $w$. We aim to probe the potential change in the SNIa
standardisation parameter $c$ with redshift and the host-galaxy of the
supernova. Improving the standardisation of SNIa brightnesses will require
accounting for the relationship between the host and the SNIa, and potential
shifts in the SNIa standardisation parameters with redshift will cause biases
in the recovered cosmology. Here, we assemble a volume-limited sample of ~3000
likely SNIa across a redshift range of $z = 0.015$ to $z = 0.36$. This sample
is fitted with changing mass and redshift bins to determine the relationship
between intrinsic properties of SNe Ia and their redshift and host galaxy
parameters. We then investigate the colour-luminosity parameter $\beta$ as a
further test of the SNIa standardisation process. We find that the changing
colour distribution of SNe Ia with redshift is driven by dust at a confidence
of $>4\sigma$. Additionally, we show a strong correlation between the host
galaxy mass and the colour-luminosity coefficient $\beta$ ($> 4\sigma$), even
when accounting for the quantity of dust in a host galaxy.
