So Cal to Colorado-- any sight seeing along the way?

That's one of the most packed road trips you can have.  Of course, your starting and ending cities do matter if you're trying to stay as direct as possible.  You have potential for: Vegas, Grand Canyon, Mesa Verde, Grand Staircase-Escalante, Death Valley, Arches National Park, various Rocky Mountain cities and national parks.  You could easily spend 2 weeks on that route if you like nature and had the time.  

That depends on where you're starting from and where you want to end in Colorado. There are two very good websites for finding things to see and do on any roadtrip in North America:

https://www.roadtripamerica.com/maps/mapwizard.php

https://www.roadsideamerica.com/

Of course, right now you'd have to check places to see if they're open or not.

Be helpful if you told us what route you plan to take.

Choices are essentially I-15 to I-70 or I-15 to I-40 to I-25.

There is a website, Roadtrippers.com that can inform you of all the sites along either route.

Any of the national parks will only be worth going into if you plan on taking the better part of day to explore in my opinion.  The parks have an entry fee, I wouldn't pay it if I was just going to do a drive through.

It depends which way you go. If you go I-40, there's really not much there to see util you get to SW Colorado. If you go I-5 to I-70, then you go through Las Vegas, and Utah. And in Utah, you can stop at Zion or Bryce Parks or any of t he many parks in Utah.