First performed (as “L’Amour est bleu”) by Vicky (1967).
Hit version by Paul Mauriat (US #1/UK #12 1968).
From the wiki: “‘L’amour est bleu (Love is Blue)’ was first performed in French by Greek singer Vicky Leandros (appearing as ‘Vicky’) as the Luxembourgian entry in the Eurovision Song Contest 1967. At the close of voting, it had received 17 points, placing 4th in a field of 17, behind ‘Il doit faire beau là-bas’ (France), ‘If I Could Choose’ (Ireland) and the winning song, ‘Puppet on a String’ (United Kingdom). Some forty years after its original release, ‘L’amour est bleu’, along with Mocedades’ ‘Eres tú’, still counts as one of very few non-winning Eurovision entries ever to become a worldwide hit.