YUV to RGB/sRGB color space conversion using ffmpeg
ffmpeg -y -i output.mp4 -c:v libx264rgb output_264.mp4
Output #0, mp4, to 'output_264.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    encoder         : Lavf57.83.100
    Stream #0:0(und): Video: h264 (libx264rgb) (avc1 / 0x31637661), rgb24(progressive), 636x360 [SAR 1:1 DAR 53:30], q=-1--1, 27.05 fps, 13524 tbn, 27.05 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      encoder         : Lavc57.107.100 libx264rgb
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 69 kb/s (default)
    Metadata:
      creation_time   : 2018-02-04T15:39:08.000000Z
      handler_name    : IsoMedia File Produced by Google, 5-11-2011
      encoder         : Lavc57.107.100 aac

ffprobe output_264.mp4
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output_264.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.83.100
  Duration: 00:07:50.02, start: 0.000000, bitrate: 1006 kb/s
    Stream #0:0(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), gbrp(tv, gbr/unknown/unknown), 636x360 [SAR 1:1 DAR 53:30], 928 kb/s, 27.05 fps, 27.05 tbr, 13524 tbn, 54.10 tbc (default)
    Metadata:
      handler_name    : VideoHandler