Might be this one?:
"Sampled cheesy dance version of TV theme Rainbow UK
There have been several dance versions of the theme tune which have been released as singles. The dance act Solo had a minor hit in 1991 with a sample-free instrumental version of the Rainbow theme, while Eurobop released a dance version in 1993 featuring samples taken directly from the original theme as well as voice samples of the main characters, who appeared on several music TV shows to promote the single; a hardcore version entitled 'Rainbow Vibes' by the Sonz of Bungle circulated on 12" vinyl in 1992 which sampled the theme tune over a chopped up breakbeat and featuring rave stabs. The most recent dance version, titled "It's A Rainbow" and featuring the vocals of Zippy and George, reached the UK top 20 in 2002."
The mentioned "solo" sounds nothing like that (and neither does Rainbow Vibes), so it has to be this one. All the aforementioned ditties are on YouTube and presumably your music streamer of choice.