The odds of a perfect match between a solid vector background created in ID and the continuous-tone raster background in a photo are slim to none unless the background was artificially added in photoshop. Honestly, your best options are to either extend the canvas in Photoshop and clone in some more background (which can be a challenge if you want it to look natural), or to change the design so the difference looks intentional. I sometimes add a paper-colored stroke to an image frame to get a clean break from a solid background which is very effective in masking the change in color.
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