If its the 5e by Roll20 sheet then the blue attribute is typically an item override or some sort of book feature that does the same thing. If you drag and drop the Gauntlets of Ogre Power from the compendium into your sheet your Str will go blue whenever the gauntlets are set to equipped. My guess is that the actual data fields the item modifies which is disabled by default, somehow has that number in it enabling it. I don't know what sheet you have but in the third tab of most sheets you should be able to find that number and set it to 0, but you also need to find how to switch off the equipped modifier or whatever that things called.
