Red had always been one of Todoroki's least favorite colors, for obvious traumatic reasons and he had never thought it suited him very well.
It's not like he would refuse to wear red or have red things, but he would not be happy about it. He would often find himself getting rid of nonessential red objects and letting any red clothing he had just sit in the back of his closet.
So you could say his distain for the color was pretty severe, that was until he had met two guys in his high school class. Katsuki Bakugo and Tenya Iida.
Of course they weren't the only people in his class that had red in their everyday looks. Kirishima, Momo, and Tokoyami being other notable people that were self proclaimed red-likers.
Bakugo and Iida did tend to wear red, Bakugo more than Iida but it was mostly their eyes that drawed Todoroki to the color.
Bakugo's eyes being confusing at first. He tended to look at Todoroki with anger or annoyance, which contributed more to the previous distain. Though over time as Todoroki started to spend more time with Bakugo and started to pay more attention to the way he would look at him the look started to become something more.
Todoroki obviously wasn't sure what this look meant. At first he was certain that it meant Bakugo was starting to become used to his company. Which made sense since he had first started noticing it while they were trying to get their Provisional Hero License with Gang Orca.
Although the gentler look did come with a different change that Todoroki didn't notice until he had started to claim Bakugo as a good friend of his. Of course there was the initial anger that Bakugo would display but their was also a bit after that.
A small blush dusting that Bakugo would hid under the pretense of "I was yelling, obviously my face is red". He didn't know it until Bakugo had confessed it to him, but the blush being a result of embarrassment and flattery. Mostly because Bakugo did consider Todoroki a good friend of his.
Iida's eyes were more consistent than Bakugo's, with a soft caring look. A gentle light amongst the usual grim and often gorey situations they ended up in as part of the hero course. The consistency and support being what mostly brought Todoroki back from his distain.
He would look at the red clothes that previously sat unused in his closet with a warm that was new for him to experience from a color alone.
He would see red things in stores or on other people and it would make him think of them, so much so he would find himself buying random objects that especially reminded him of their eyes. Things like jewelry, clothing, miscellaneous children's toys, and the occasional pen.
As they got older the things he would buy started to change. He would buy all the merch that depicted their faces and keep them in small store boxes just for safe keeping. Soon it moved on from just the ones with their faces to all their merch because now seeing the colors blue and silver, orange and black would remind him of red and of them.
That was it, he was officially a red-lover. He couldn't get enough of the color and the comfort that it brought to him. The love that he felt being reminded of two of the most important people in his life completely eclipsing any negative connotation left.