“colors running” is an issue with dyes or paint not staying where it supposed to on something, so like washing a piece of clothing and the colors fading or staining some other part. Originally it references paint “running” off something in small streams, like if you applied to much. Running being a word commonly used to describe the flow of a stream or river, so if paint is coming off something in small streams, it would be described as “running”.
“The colors” also being a euphemism for a flag or standard on a battlefield, historically formations on a battlefield having a flag that would act as a clear point to focus around during the chaos of a battle, hence the saying “rally around the colors” meaning “ find the flag of the unit and defend it, if you don’t know what to do”.
So shirts with a flag that say “these colors don’t run”. it’s a double entendre, saying that “those that this flag stands for will not run away from a fight” and that “the dye on this clothing will not get distorted”.
In the context of a trans flag, it is a parody of vocally/excessively patriotic people who would wear an American flag shirt with that saying on it.
It would be easier to list the things she didn’t do.
Long and short, screwed over a lot of minorities, oversaw a lot of violent conflicts, and reshaped the UK economy and government to benefit the financial sector and ultra wealthy at the expense of everyone else.