Believe it or not, you can change how your crosshair looks in 1.8.9 without installing a single mod. However, the options are limited to Scale and Color.
Vanilla Minecraft 1.8.9 has a terrible crosshair selector. You need mods. Here are the industry standards. crosshair minecraft 1.8.9
Resource packs are one of the easiest ways to customize your Minecraft experience, including the crosshair. To change your crosshair using a resource pack: Believe it or not, you can change how
Apply the Resource Pack: