Colorize this existing black-and-white video with plausible natural colors. This is colorization, not a new scene or a style replacement. Keep exactly the same woman, facial features, hairstyle, pose, glance, blink, hand positions, cup, envelope, table, window, camera framing, timing and motion. Add natural warm-neutral skin tones, dark brown hair, a muted beige trench coat, a medium brown wooden table, an off-white ceramic cup and white envelope. Outside the window use softly muted blue-gray rainy daylight and natural building colors. Preserve the original soft lighting, shadows, texture and film detail. Apply stable colors consistently throughout every frame with no flicker, hue pumping, object morphing, beauty retouching, new objects, text or camera movement. No sepia, no monochrome, no strong cinematic tint, no cartoon look.
