Most channels are colour. One channel is black and white. It's not an old movie — it's a modern broadcast. Your seller's colour encoding is broken for that specific source.
Here's a short relatable scenario: colour video uses a colour signal (chroma) on top of a brightness signal (luma). If the chroma signal is lost or misrouted, you get black and white. A British IPTV reseller with sloppy encoding sometimes drops the colour signal for individual channels.
In most cases, you can't fix this. The seller must repair their encoding for that channel. A good British IPTV seller will investigate and fix. A bad seller will say "that channel is black and white" — which is false unless it's a vintage broadcast.
What actually works is reporting the exact channel and timestamp. A good IPTV reseller UK will check their logs and likely find a dropped colour flag. An amateur will ignore you.
Let me give you a real example. A user's British IPTV showed a major sports channel in black and white. Every other channel was colour. Support said "it's the source." The user checked the source via an antenna — it was colour. The seller's encoder was broken.
Most operators find that single‑channel colour loss is almost always the seller's error. Push for a fix.