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 continuity mistake in show generally
Cygnus! Hyogen no senshi - S1-E3
Audio problem: To satisfy his weird mother fetish, Hyoga dives with a rose in his mouth, but that does not prevent him from shouting his battle cry. (00:07:00)
Kiseki no fukkatsu! Yuyo no cosmo - S1-E5
Trivia: When Seiya opens his eyes hearing Miho calling his name, behind her in the audience a particularly bored animator decided to put in some silly characters, including the Tin Man, the Lion and a girl with the look of Dorothy from the wizard of Oz. (00:19:20)