So here is the final version I said I'd made. Nothing much different. Darker blue, And added the star.
Looks good, but I don't know if you discussed about the legend that explains why it is 4 red on yellow in the original Catalonian-Aragon flag ?
http://en.wikipedia.org/wiki/Senyera
According to a 14th-century legend, the flag dates back from the 9th century, when the four red bars were drawn, as an act of gratitude, on Wilfred I the Hairy's (Count of Barcelona) golden shield by king Charles the Bald's fingers drenched with blood from the Count's war wounds prior to Wilfred's death in 897 during the siege of Barcelona by Lobo ibn Mohammed, the moor governor of Lleida. This legend would relate the emblem unambiguosly to the Counts of Barcelona title.[2]
Romantic-driven Catalan nationalists were particularly keen on this legend during the Renaixença, in the 19th century, albeit it has always been recognized and divulged as such even in patriotic circles. Charles the Bald had died 20 years earlier, in 877.
Another version of this legend cites Louis the Pious as the king drawing the bars during the conquest of Barcelona, in this version drawing them in a golden shield, but Louis died before Guifré was born.[7] Also, Barcelona was conquered long before the events described on the legend.[7] Another medieval variant of the legend features Ramon Berenguer painting the bars with his own blood on a yellow shield, with the yellow field of the shield being the arms of Aragon before his marriage.