Analysis of information sources in references of the Wikipedia article "Federal League (1815–1820)" in English language version.
The red, blue and white colours were used by Artigas to establish a clear difference between the flag of the Eastern Province. These three colours evoke the colours of the French Tricolor of French Revolution days. At the beginning of the 19th century, red and blue were the colours you could find when looking for cloth for the soldiers' uniforms, in these Spanish colonies. Materials came in two shades of blue. One, the lightest, was celestial or "heavenly" blue and had been chosen by Belgrano for the flag of the May 1810 Revolution. Four or five years later, not wanting his colors to be similar or confused with those of the Buenos Aires government, against whose dominance he would be soon fighting, Artigas chose to design his flag and other provinces which were with him in opposing of Unitarian domination, in colours not existing in the Argentine flag. The shade of blue he adopted therefore was navy blue. Jorge Cajarville, 16 Jun 1999
