Hi!
What is the title of this old movie, probably 1970´s a little in the style of "Clash of the titans", fantasy-esque, I think there was an unicorn/flying white horse, and this guy and girl, he sets out to find a blue rose but there is none, and in the end he has a (white ?) rose and says something like "If you love me, this rose IS blue" and she looks at him and the rose turns blue. That´s all I remember, thanks!

Think you're looking for this: (if you scroll down to the user review area on the first link, the first line mentions the blue rose... )

The Thief of Baghdad (1961) - IMDb

The Thief of Baghdad (Full Movie) - YouTube

Yeah that´s got to be it! I took a look at part 9/9, and sure enough about the rose. Gee I didn´t realise it was such an old movie, I probably watched CotT in the near time of watching this and got them mixed up.

:)