Fix Typo

Author: WebDevSimplified

src/pages/2022-01/intersection-observer/index.mdx

@@ -107,7 +107,7 @@ observer.observe(document.getElementById("test"))
 
 <IntersectionObserverComponent rootMargin={-50} />
 
-As you can see from the blue lines our new viewport is 50px smaller. This type of rootMargin is perfect for doing things like loading animations that you want to occur after an element is at least a certain distance from the edge of the screen.
+As you can see from the red lines our new viewport is 50px smaller. This type of rootMargin is perfect for doing things like loading animations that you want to occur after an element is at least a certain distance from the edge of the screen.
 
 ### Root