Continuity mistake: This is repeated with all the main characters throughout the series: whenever someone puts on their clothes, their pants underneath change colour (for example, Seiya's blue jeans turn red).
Saint Seiya (1986)
1 mistake in show generally - chronological order
Kiseki no fukkatsu! Yuyo no cosmo - S1-E5
Trivia: When Seiya falls down during the victory celebration and the three kids scream (the shot that comes before the one where Miho drops the picture) you can see briefly in the audience between the kids an easter egg appearance of Magical Princess Minky Momo, a character from a different anime. (00:13:50)