I need help fixing my sidebar…

https://www.sydlexia.com/news/

After switching over to 1.5, a couple of things change in my sidebar. The Calendar heading as well as my Links heading are now in purple instead of green like they were. Also Links has a purple line under it, whereas they all used to have green lines. For the life of me, I can’t find what file holds this information so I can edit it. Does anyone know where it is? It doesn’t seem to be in the index file in my theme….