Yes — that first black-and-white view is typically the embedded preview JPEG from the camera. Your Canon’s monochrome picture style affects that preview, live view, and JPEGs, but a RAW/CR3 file still keeps the full captured image data, including color information.

That’s why Lightroom or another RAW editor may briefly show the embedded preview, then replace it with its own RAW rendering, which appears in color unless you apply a black-and-white conversion in software.

This is normal behavior and is the point of RAW: it preserves the original capture so white balance, color, sharpening, noise reduction, aspect ratio, and styles can be decided later in post-processing rather than being baked in.

If you want the final image in black and white, convert it during editing in Lightroom or similar software. If you want the camera’s monochrome look permanently applied straight out of camera, shoot JPEG instead of RAW, or RAW+JPEG if you want both flexibility and an instant black-and-white version.

The grainy look when zooming is usually from viewing the RAW render at high magnification before sharpening/noise reduction or full preview generation has been applied.