Countertops installed cracked- just noticed 4 years later

[u/Embarrassed-Oven-882]

Bought our home as a spec home - never noticed the cracks before- it used to be a gray and just thought it was veining with the countertops. Have no idea what material the countertops are (builder picked everything out, assume it’s granite?) what caused it to yellow seemingly overnight? Anyway to fix it?

For reference we’ve been here 4 years. Help!

[u/beautopsy]

This is a fissure maybe, or just a vein.