If you find the default Blizzard numbers too small or hard to read, most veteran players use addons to make them more dynamic. Popular options include: MikScrollingBattleText (MSBT):
Here is the brutal truth: If you want red numbers for Fire damage, green for Nature, or a custom font like "Impact," you must skip to Part 4 (AddOns). how to enable damage numbers in wow
If you want to specifically see green numbers when you receive healing, this is still available in the default settings for some versions: Check the box for Scrolling Combat Text for Self If you find the default Blizzard numbers too
There are two main ways to see floating damage/healing numbers in WoW: using the game’s built‑in combat text (via Interface options) or a popular addon (more flexible). Below are step‑by‑step instructions for both. I assume default UI and the current retail version. Below are step‑by‑step instructions for both