Das sieht alles blau aus
I have translated as "that seems all blue", and it was labelled as a mistake. Why? Thanks!
"that seems all blue" = "das sieht ganz blau aus"; "all that seems blue" = "das sieht alles blau aus"
So, the word "ganz" describes the adjective (blau), and the word "alles" describes the subject (das)? Or something like that?
"ganz blau" -> "ganz" is an adverb describing "blau"; "das (...) alles" -> This is the subject of the sentence ("alles" is a pronoun). Alternatively, you could say "das alles sieht blau aus", "alles das sieht blau aus" or "all das sieht blau aus".
In the original sentence, "Das sieht alles blau aus.", it looks to me as if "Das" is the subject, and "alles blau", coming after the verb, is the adjective. So I would have done the same as andrear, and translated it as "That looks all blue." Except that "alles" has the -s on the end, so I suppose that means it's attached to the word "Das". Which would give "That all looks blue." The word order is what confuses, I think.