I know this varies by states so asking bought colorado
If im carrying my handgun or say a hunting rifle and get pulled over do i legally have to inform the officer im carrying. Back in indiana id normally just had hand the officer my license and my conceal carry permit as not to have to say hey officer i got a gun. Doing so always ended with a happy officer never pulled out and checked.

If its not legal i font fell the need to but normally do to avoid issues later ie them seeing it when i reach for the glove box for paperwork or if its in the glove box or incase i get pulled out gor some reason

Just wonna follow colorado law. We all know the im sorry i didnt know officer or well back in indiana ant a defense