After sharing, then unsharing them and touching them up for months, today I finally reached a stage where I am happy with both of these liveries.
GT3 EVO Italia
My recreation of the official 2018 Super Trofeo EVO:
Official RGB values from Italy’s latest clarification on the national flag in 2006 converted to Forza’s HSB values:
Green
H 0.39
S 1.00
B 0.38
Red
H 0.97
S 1.00
B 0.87