He also noted the song's "genuinely heartbreaking melody which has that bristling shiver down the spine which hallmarks classic pop from all eras past".
[1] Mark Cooper of Number One considered both "Mr Blue" and "Unmarked" to show Clarke "develop[ing] his social conscience" and "dealing military madness a blow or two".
[4] Stuart Cohn of Rolling Stone picked "Mr Blue" and "Softly Over" as the best songs on the album, with both setting "ambiguously worded love lyrics to traditional-sounding, hymn-like melodies".
Leading up to his appearance, Klijn requested to perform "Mr. Blue" at the end of the show and he agreed that De Leeuw could accompany him by singing with him during the chorus.
Klijn then recorded a studio version of the song, which featured contributions from Cor Bakker, Candy Dulfer and John van Eijk.