Emily, I'm not sure about your workflow. Why are you creating a new document to paste the Photoshop file into? The new document you create has no connection back to Lightroom. However you say you are not returning to Lightroom, so maybe that doesn't matter. When the photo opens in Lightroom, do you see the Lightroom edits? Or, to be more clear, does the photo look like you expect it to with the edits you made it Lightroom? Here's what I think is happening. I think the color space is changing, and that is changing the look of your image. It's not really that you are losing the Lightroom edits. By default Lightroom sends images to Photoshop in the ProPhoto color space. When you create a new document with a web template, the new document is created in the sRGB colorspace. When you paste the photo into the new document the colors get shifted. Default color settings have all warnings turned off so you wouldn't know this is happening. Try this, open your photo in Photoshop, and before you copy it, go to Edit>Covert to Profile and choose the profile starting with sRGB in the name. Now do your copy and paste and see if the colors stay the way you expect them to.
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