I believe you are referring to the embossed pattern (that makes it look/feel realistic) that is holding the dirt. This is normal for heavily textured surfaces (imagine how much dirt a raw brick floor would hold vs slick sheet linoleum). This looks WORSE with VERY PALE floors (like the Whittier Oak).

The best defense against "dirt" is to stop it before it enters the house. Lots of mats at the entrances. The "shoes off" requirement, etc.

Now that the dirt is present, you will need to look at how your are cleaning. Most people have a form of mopping that just moves dirt from one space to another. Water evaporates but DIRT particles remain. That often means adding in TWO MORE steps into your mopping/cleaning regime. I call this the DEEP CLEAN.

Step 1: Damp mop as normal (please use only the allowed cleaning products stated by CoreTec)

Step 2: RINSE the floor AS YOU GO (using a second mop with a bucket of "clean" water)

Step 3: HAND DRY the floor AS YOU GO (clean towels used to wipe up the rinse water)

Sigh. I know this sounds like a lot of effort. Once you do this a few times in a row (some have had to repeat this 3-4 times before they were happy with their floors), you can go back to your regular mopping technique. This DEEP CLEAN (with all three steps) will turn into a 2-3 times per year event. Even less if you can retrain the people in your home.