A tip on colour schemes is to try and keep to using 3 or 4 colours max and not to crowd an area with too much of one colour, especially if two items have the same colour (spear shaft and armour would be a good example here). This rule generally only applies for costume, so don’t worry about weapons or skin and stuff like that, but I’d keep the shield’s colour the same colour as the armour, and keep all the armour the same general colour to give consistency. Think about what colours work well together, what makes what stand out, for example you’ve used red against green here in the torso area. Having a green background makes the red foreground stand out because they are contrasting colours, but it wouldn’t work the other way round because red is a much stronger colour than green. And don’t be afraid of using different shades of the same colour to add variety.
Hope this helps.