Remove Sun-Bleached Hair Stripes

I have a high-resolution portrait where two harsh white stripes created by direct sun run through a man’s hair. I need those streaks blended perfectly into his natural shade so the overall color looks true-to-life, without any tell-tale signs of editing. No artificial stock filters or automated “one-click” fixes—this has to stand up to close scrutiny when printed at poster size (A3 / 12 × 18 in, 300 dpi). Please work in Photoshop, keeping all original detail and hair texture intact. The finished file should be supplied as a layered PSD (so I can toggle your work if needed) plus a flattened high-quality JPEG or TIFF ready for print. Colors elsewhere in the image should stay faithful to the original; I only want the sun-bleached stripes corrected, not an overall saturation boost. Acceptance check: under magnification the repaired areas must match surrounding hair color and grain, with no halos, blurring, or pattern repetition.