A lot of value for an old sports Rolex is in the dial ..... and a 'repainted' dial certainly reduces value. If it's a fully repainted dial, a lot of collectors would reject the watch completely.
A 'relume' is a different story. This means the original dial is intact and correct but the plots have been touched up. Once again, a watch with a relumed dial will value lower than a comparable watch with a totally original dial. Some collectors will accept a relumed dial though, particularly if it's been well done and all else is ok.
And even with the crazy prices we now see for vintage sports Rolex watches, a late 60s GMT with a repainted dial is not worth 10,000 euros.