I'm afraid I just blue myself...
A lot of Tobias' lines must not make sense when translated into other languages.
I seem to remember that 'Ich bin blau' translates, colloquially, to 'I am drunk', so could one translate this as saying 'You all like the drunk man'?
no, that's not possible here. As you say the frase is: Ich bin blau. Du bist blau. blau sein.
Ein blauer Mann, reminds more of ein Blaumann than of being drunken, that's a blue working suit for non businessmen.
There are also other frases with 'blau' like 'blau machen' ~ having a break.
Because 'ihr' is plural 'you' when used as the subject. It's 'her' when used as the the direct object (Der Mann mögt ihr)
Actually your example should be "Der Mann (mag) (sie)"
And (ihr) is "her" if it's only used as possessive pronoun
eg. "Her brother is a doctor" = "Ihr Bruder ist ein Arzt"
or in dative case
eg. "I'm going to Germany with her" = "Ich gehe nach Deutschland mit ihr"
When adjectives are on the other side of a linking verb, they don't change ("Der Mann ist blau"); that's called a "predicate" adjective. But when they are right next to the noun they're modifying (called "attributive"), they change form to match the gender, number, and case of the noun. So "blau" becomes "blauen" for the same reason that "der" becomes "den": it's the masculine accusative form.
Note that adjectives have multiple declension patterns, depending on definiteness - if you have a definite article, like "den" in this case, you use the "weak" pattern, in which the only two endings are -e and -en: -e for masc/fem/neut nominative and fem/neut accusative, -en for everything else. See http://en.wikipedia.org/wiki/German_declension#Attributive_adjectives
It's worth to mention it's weak inflection in the acusative case. ^^ http://en.wikipedia.org/wiki/German_adjectives#Weak_inflection
Until today i didn't know that adjective inflections follow the rules of the cases.. another complication.. wow.. I'm so happy
Same basic meaning, different emphasis. Similar to the effect of the English "It's the blue man you like."
Should DL accept 'you like man IN blue (shirt/clothes etc)' too? I got it wrong. :(