§ 1. Open "slope.jpg" image file. At this time let's try to edit the girl's top without affecting the rest of the image.

§ 2. Pull down "Image > Adjustments > Replace Color..." The masking and adjusting tools appear in one dialog box - a hybrid of "Hue/Saturation" and "Select Color Range" commands.

§ 3. First of all, we have to select the red area. Click with the "eyedropper" (it is already active) somewhere on the cloth. See on the preview what areas are selected.

§ 4. Activate the "Add to sample" eyedropper and click several more times on other hues of red so that to select all the red tissue. If necessary, remove mistakenly selected areas with "Subtract from Sample" eyedropper.

§ 5. Adjust the color sensitivity of the tool with the "Fuzziness" slider.

§ 6. It seems that the top is completely separated from the girl* and we may adjust its color. Move "Hue", "Saturation", and / or "Lightness" sliders until you achieved a desired result.
*Note though that the lips are separated as well.

NB Alternatively, you can click the "Result" color swatch in the dialog and choose a color with the Color Picker. Note though that this method is recommended only for similar color. That is, choosing, e.g., red color instead of green may not work.