Welcome to the community, and sorry for the issue. Could you share comparison screenshots of the footage? That would help us understand the issue better. Is it only the export file that is affected, or is your preview different? Are you working with HDR media? If so, please refer to these links:
This video discusses and demonstrates some newer settings in Premiere Pro that may be affecting your newer camera footage. If you're seeing blown-out footage in Premiere Pro CC 2022 (version 22.0 and newer) then this simple settings change may correct that, and prepare you for the future of HDR ...
" ... the color of the imported files does not match with the original files?"
First, how are you determining what the image should be correctly? No camera made, not even the $70,000 RED, Arri, and Sony rigs, has an accurate screen. Anyone using even those on-set also has a highly calibrated monitor if they intend to check image values.
And very few computers between the OS and monitors actually show an accurate image view. Which is why most pro colorists require that you only base comments on their grade while viewing on an approved screen, either in their suite or typically one they provide. Colorists never work from standard monitors connected to a GPU.
So yes, how and with what you view the image is crucial to seeing accurately what your image data is. And telling us what you're basing your understanding on gives more information on how to assist seeing it most accurately.
Especially as Premiere is actually far more likely to be showing (internally) a correct image view than about anything else on most computers. It follows the pro standards very tightly. And most users should have the Preferences option for Display Color Management clicked on, as that allows Premiere to very tightly try to show the correct image on whatever monitor you are using.
But in hazarding a starting guess, this could be one of several things. I'll cover the two most common quickly.
Mac OS ColorSync color management issues
Ther first is if you are working on a Mac, and comparing the image to outside of Premiere, say in QuickTime player, on that Mac. Apple chose to have ColorSync ... their OS color management utility app ... use the wrong gamma for displaying SDR/Rec.709 media.
The proper display gamma for Rec.709 is 2.4, with 2.2 permissable in bright-room environments and project designed for web use.
ColorSync applies the camera transform gamma of 1.96, rather than the display gamma of 2.4. Which means that a typical SDR/Rec.709 file played under ColorSync control will appear to have lightened shadows and lowered saturation.
Conversely, if that same file is shown with proper 2.4 gamma, it will (compared to the ColorSync view) have darker shadows and higher saturation.
There is no fix for that very frutrating situation. My many colorist buds, most of them total Mac geeks, are furious with Apple over this.
Color Management Mismatch with HLG clips on a Rec.709 Sequence
This has become common as most iPhones and many DSLRs are defaulting to shooting in HLG, an HDR form. With Premiere's new (to the 2022 version) color system, the user now must apply correct color management choices when dealing with media.
When you drop a clip in the HLG color space onto a Rec.709 timeline, you have a mismatch. Even if you bring the whites down so they look ok, on export Premiere will show that HDR clip with HDR values in the SDR export. Blown out.
SDR/Rec.709 Workflow with HLG Media
Select one or more clips in the project panel
At the bottom, in the new color management settings, set the Override-to option to Rec.709
Make sure your sequence CM is set to Rec.709
Use a standard Rec.709 export preset ... avoid any with HLG or PQ in the preset name.
Doing so should fix any color mis-manglement issues. I've appended some links that also could be helpful.