They share a common border.
California to Colorado, obviously!
Lakewood, Colorado and West Valley City, Utah are 371.81 miles (598.36 kilometers) apart
If you are driving or flying to Colorado or Utah from California, Colorado is farther away.
689 miles
Colorado's western border is shared with Utah.
It is 355 miles according to Google Maps.
It is 630 miles according to Google Maps.
Colorado is "further away" from California than Utah is in the sense that, given a pair of points in Colorado and California, there is at least one point in Utah which is closer to the point in California than the point in Colorado is.
51,oo meters
No, it's in Colorado.
California to Colorado is further than California to Utah.
Colorado lies east of Utah. Utah lies to the north-east of California. Therefore, Colorado is farther from California. See the link for a map.