If your 7D RAW files look unusually flat or nearly colorless in Canon DPP, the most likely causes are either a DPP settings issue or a corrupted installation.

Things to check:

• Picture style/settings in DPP: make sure a style or monochrome-like adjustment is not being applied.
• Fast display / preview options: disable any fast display setting if enabled.
• Color space settings: verify DPP is using the correct color space.

Since the camera preview looks normal, the RAW files themselves are probably fine. A camera LCD shows an embedded JPEG preview, while DPP renders the RAW file using its own settings, so software configuration can make the image look different.

If those settings look normal, reinstalling or updating DPP is a good next step. One community answer indicates the installation may have been corrupted, and reinstalling the latest version resolved the issue while keeping preferred settings stored separately.