Never-Twice-(the)-Same-Colour is an early standard for American Visual-Distortion-Units (or VDU's). It is the American equivalent of the PAL (Perfectly-Acceptable-Lightwaves) standard. One of the most fascinating (or annoying) features of the NTSC standard is that every device which claims to conform to the standard in fact renders images in totally different colors. Historically it has also resulted in smaller display resolutions as a result of extra hardware required to color-correct the display during the vertical blanking interval. Supporters of the standard claim it is now much better and only has problems when displaying color.