Orange Wings Set

Ahead of the new millennium, Countdown ushered in the third and final instalment of its beloved wings set; this time, seeing the design be rejuvenated by lots of bright orange. It debuted in the first episode of the Championship of Champions X tournament on 27th December 1999, and represented the biggest overhaul that the set's principle design had underwent in its decade-long tenure. The revamp took place as part of a regular refresh to the programme, which generally saw a new logo and opening title sequence be introduced. Along with these changes, Countdown began broadcasting in, what was then, the relatively new 16:9 (widescreen) aspect ratio, replacing the 4:3 aspect ratio used beforehand.

The 2001 titles, unveiled in Series 45, started the movement of utilising the Countdown clock as the key subject. They comprised the camera slowly panning out from the clock face for the duration of the 30 seconds. Throughout the sequence, various clusters of letter and number tiles flew into the centre before flipping over to reveal clips of Richard and Carol, whose on-screen relationship had become a significant attribute to the show by this point. At the end of the sequence, a set of wings faded in behind the clock, while nine letter titles formed a line-up in front, spelling 'COUNTDOWN'. The initial version of the titles inadvertently had the 1989–1995 theme tune playing over them, therefore were redone towards the end of the series with the correct music and new clips of Richard and Carol. This sequence was carried over with the set revival in 2003, with the clips changed accordingly, and a fourth variant was introduced in April 2005 with enhancements to the shadow under the letter tiles.

Aside from the new colour palette, the main studio area remained how it had been on the preceding style. The boards area, however, situated to the immediate left, was heavily redesigned and no longer included the conundrum board; instead, this was transferred to the other end of the studio. This allowed for a wider clearing between the two remaining boards so that they wouldn't obstruct each other in the new widescreen shot they would appear in. Both boards were given a blue and pale yellow colour scheme, with the blue as an accent colour around the edge of the board to match the background of the tiles and box labels. For the first time, the pockets that the tiles were placed onto matched the appearance of the boards themselves rather than using standard (black) magnetic sheets. This was achieved by applying coats of magnetic primer and masking over them with the board's equivalent emulsion colour. Another change made for this set onwards was the way in which CECIL and the contestants' scores were displayed, whereby the LEDs in the seven-segment displays were upgraded to show the digits in a more bright and narrow fashion. The scoreboards were also placed higher up on the desk than they had been on the two previous wings sets.

Some subtle changes, primarily involving various set pieces being repainted, were made to the orange wings set during its time in production. The most prominent was given to the desk, which was originally grey prior to becoming beige. The letters and numbers boards mimicked the desk's beige colour scheme at first, but later benefitted from a splash of orange to liven them up slightly. A few months into the set's tenure, the clock hand was tinged differently, from marble-textured black to the blue that is still used on it today to match the clock's border. Finally, multiple periods from the end of 2001 onwards saw the use of significantly darker studio lighting than usual and the clock face be filtered in purple, notably during the finals stages when the set was decorated for Christmas.

This era covered the final series to use the 9-round format (Series 45) that had been in use since the programme's inception. At the start of Series 46 in September 2001, the arrangement of the game changed to what is now known as the original 15-round format as a result of Countdown's transmission time being extended from half-an-hour to forty-five minutes. Unlike the previous format, in which both contestants had an equal amount of letters and numbers selections, the new format gave the contestant in the champion's chair an additional pick of letters, but only one of three numbers choices: an apparent advantage to the player in the challenger's chair in the event of a close game. The format is generally summarised as LLLLN LLLLN LLLNC by the show's fanbases, where each letter represents the type of round: L for letters, N for numbers, and C for conundrum.

The grand final of Series 48 was the last episode to be filmed in the orange wings set — although, for its final weeks in production, it was filtered entirely in purple. This concluded the use of the wings style altogether after eleven years. Despite the upcoming radical overhaul to the set being highly anticipated by Richard Whiteley in the final shows of 2002, it was met with criticism from viewers when revealed in the first episode of Championship of Champions XI in January 2003.