# Color frame sequence > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Color_frame_sequence > Markdown URL: https://mediated.wiki/source/Color_frame_sequence.md > Source: https://en.wikipedia.org/wiki/Color_frame_sequence > Source revision: 1353581429 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Frame sequence for color composite video signals In [video engineering](/source/Video_engineering), the **color frame sequence** is the sequence of [fields](/source/Field_(video)) in an [analog composite video](/source/Composite_video) signal through which the video frame timing and [chrominance subcarrier](/source/Chrominance_subcarrier) signal timing—in particular, that of the [color burst](/source/Color_burst)—cycle through all possible phase relationships. The process of maintaining this alignment through the process of analog composite video recording, editing and broadcast was known as **color framing**. The exact nature of the color frame sequence depends on the video standard being used. In the case of the two main composite video standards, both of which use analog [quadrature amplitude modulation](/source/Quadrature_amplitude_modulation) for the chrominance signal, [PAL](/source/PAL) has an 8-field (4 frame) color frame sequences, and [NTSC](/source/NTSC) has an 4-field (2 frame) color frame sequence.[1] Because it uses [frequency modulation](/source/Frequency_modulation) for the chrominance subcarrier, [SECAM](/source/SECAM) does not have the subcarrier phase sensitivity problems of NTSC or PAL, but a field phase sequence was usually imposed to reduce visible artifacts on monochrome receivers.[2] ## Use in analog videotape editing Preserving the color framing sequence of video across edits and between channels in video effects was an important issue in early analog composite [videotape editing](/source/Videotape_editing) systems, as cuts between different color sequences would cause jumps in [subcarrier](/source/Subcarrier) phase, and mixing two signals with different frame sequence alignments would result in color artifacts on the part of the signal that was not in sync with the output color frame sequence, rotating that signal's colours within the chroma color space.[2] To help prevent these problems, Bit 11 of the [SMPTE timecode](/source/SMPTE_timecode) frame is the Color Frame Flag, which can be used to indicate the timecode is aligned to the color framing sequence so that composite video editing equipment could make sure to edit only on appropriate color frame sequence boundaries in order to prevent picture corruption.[3] Specific definitions of this timing relationship were defined for both NTSC and PAL colour standards.[4] If the color framing bit was set in both types of material, the editing system could then always ensure that color framing was preserved by constraining edit decisions between input sources to keep the correct relationship between the timecode sequences, and hence the color framing sequences. ## Obsolescence Color framing has become largely an issue of historical interest, first with the advent in the 1980s of digital composite video [timebase correctors](/source/Timebase_corrector) and [frame stores](https://en.wikipedia.org/w/index.php?title=Frame_store&action=edit&redlink=1), which could regenerate the color frame sequence of a composite signal at any phase, and later with analog [component video](/source/Component_video) editing and modern [digital video](/source/Digital_video) systems, in which subcarrier phase is no longer relevant. Color frame sequence considerations are thus only relevant to remaining archived composite video recordings, and even those are typically dealt with automatically in the process of digitization. ## See also - [Field dominance](/source/Field_dominance) - [Dot crawl](/source/Dot_crawl) - [Colour recovery](/source/Colour_recovery) ## References 1. **[^](#cite_ref-1)** ["Understanding Analog Video Signals"](https://www.analog.com/en/resources/technical-articles/understanding-analog-video-signals.html). *analog.com*. 18 September 2002. 1. ^ [***a***](#cite_ref-:0_2-0) [***b***](#cite_ref-:0_2-1) Mohamed, Sadiq (December 2015). ["COLOUR FRAMING What does it mean, and why won't it go away?"](https://editorsbench.co.uk/documents/CF2015.pdf) (PDF). 1. **[^](#cite_ref-3)** ["SMPTE QuickGuide"](https://support.etcconnect.com/ETC/Getting_Started_with_ETC_and_FAQ/SMPTE_QuickGuide). *Electronic Theatre Controls Inc*. 2018-05-14. Retrieved 2026-04-23. 1. **[^](#cite_ref-4)** ["RECOMMENDATION ITU-R BR.780-2 Time and control code standards, for production applications in order to facilitate the international exchange of television programmes on magnetic tapes"](https://www.itu.int/dms_pubrec/itu-r/rec/br/R-REC-BR.780-2-200504-W!!PDF-E.pdf) (PDF). *www.itu.int*. 2005. v t e Analog video standards RF connector Composite video S-Video (Y/C) Component video YPbPr RGB v t e Analog television broadcasting topics Systems 180-line 343-line 375-line 405-line (System A) 441-line 455-line 525-line (System M) 625-line (System B, System C, System D, System G, System H, System I, System K, System L, System N) 819-line (System E, System F) Color systems NTSC NTSC-J Clear-Vision PAL PAL-M PAL-S PALplus SECAM Video Back porch and front porch Black level Blanking level Chrominance Chrominance subcarrier Color burst Color frame sequence Color killer Color TV Composite video Frame (video) Horizontal scan rate Horizontal blanking interval Luma Nominal analogue blanking Overscan Raster scan Safe area Teletext Television lines Vertical blanking interval Vertical interval timecode White clipper Sound Multichannel Television Sound NICAM Sound-in-Syncs Zweikanalton Modulation Frequency modulation Quadrature amplitude modulation Vestigial sideband modulation (VSB) Transmission Amplifiers Antenna (radio) Broadcast transmitter/Transmitter station Cavity amplifier Differential gain Differential phase Diplexer Dipole antenna Dummy load Frequency mixer Intercarrier method Intermediate frequency Output power of an analog TV transmitter Pre-emphasis Residual carrier Split sound system Superheterodyne transmitter Synchronization of TV transmitter and receiver Television receive-only Direct-broadcast satellite television Television transmitter Terrestrial television Transposer Digital television transition Frequencies & bands Frequency offset Microwave transmission Television channel frequencies UHF VHF Propagation Beam tilt Distortion Earth bulge Field strength in free space Noise (electronics) Null fill Path loss Radiation pattern Skew Television interference Testing Distortionmeter Field strength meter Vectorscope VIT signals Zero reference pulse Artifacts Dot crawl Ghosting Hanover bars Sparklies --- Adapted from the Wikipedia article [Color frame sequence](https://en.wikipedia.org/wiki/Color_frame_sequence) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Color_frame_sequence?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.