Is it likely that the raw data from the image will be used for future analysis? If so, I think you are better off not applying any manual corrections to the images, or at least give enough detail that a reader can undo your changes to reproduce the data you started from exactly. If not, I think it's probably ok so long as you are upfront about what you did, although my personal feeling is that you generally shouldn't do more than standard-in-your-field and easily explained tweaks (as I'll explain below).
Keep in mind that "I altered the data" will be a red flag for some subset of people, even if the changes are minor and you only made them for aesthetic reasons, so you need to be prepared to explain exactly what you did and why. Sometimes, it's easier to give up on aesthetics in order to avoid this discussion, which can easily (and pointlessly) distract people from the main points you want to convey in your paper.
If you do show altered images, you need to use your judgment about exactly what and how much to say. If it's standard in the field to, say, adjust the contrast of the image, this probably doesn't need more than a passing mention. In this case, it's probably enough to say something like "Note: the images in this figure were adjusted for contrast; the raw data are available at X" (assuming you are releasing the raw data in some supplemental material).
But I suspect the more advanced (and likely proprietary) Adobe Lightroom tools you are talking about like color grading are not commonly used. For the rest of this answer, I'm going to assume we're talking about using such a non-standard, black box tool primarily for aesthetic reasons (as opposed to something like contrast, which is relatively easy to understand). Even if the changes you make the data are "minor" in that they don't affect your conclusions, you generally should only modify data displayed in a results figure for a well-explained scientific reason. Even if you don't notice any major differences, people may see things you miss and be misled by an artifact of your post processing.
One way to explain why this is important that the "results" section should show your results without any interpretation, while the "discussion" section should have your interpretation of the results, so that readers can take your results and give a different interpretation if they want to. Modifying the image in a way that you claim does not change the main results necessarily relies on your interpretation of what the most important features of the image are. Another way to express the point is to ask yourself how sure are you that (a) the black box tool you are using won't introduce any subtle artifacts that could be misunderstood as an important feature, and (b) that you can explain why it won't to a skeptical person? I wouldn't recommend proceeding if you aren't very confident in your answers to both questions.
Finally, what you show in a paper should be reproducible, at least given some reasonable starting point. Adjusting a slider on a black box tool until the image looked good to you is probably difficult to explain in a reproducible way. More pointedly, "I added tint to the image so it looked better" is a hard thing to justify to a hard-nosed referee.
