@Train Track
No. It doesn’t depend on that. Colors looking good together is a science we figured out centuries ago. And FIM knows how to use just the right tone of each color to make these colorful ponies look good rather than garish.

But even though this guy stands out as an OC, it’s not something I would’ve even commented on if it wasn’t already being discussed. Because his colors aren’t that “jarring”, at least not on my monitor. Like if you toned down just the mane a little, that’d probably be enough.

Take a look at official characters that are blue and red and use the color picker in any art program to see what tones the show uses if you want to see what a more normal level of color would look like. This should help you make your OCs look more like they belong in the FIM world.

Looked through your OC tag, and there are some rare images where his colors look better, and others where they look worse. Also spotted another OC in a group pic with Train Track who I remember took ages to finally update his colors to look better. If he’s a friend then didn’t that change inspire you to think about an update too? The sooner you get those colors just right, the better… Is something I’m quite slow in saying. 3 years and 200 images made where he’s too bright might seem like “too late” but it never is.

Also what’s the context of this image? What they talking about?

@Background Pony #AA91
I guess it depends on what colours you like.

@Train Track
Bright red and bright blue are non-complementary colors (traditionally when used together one is a dark variant) When used together they can be overwhelming to a persons eyes.

@Background Pony #AA91
What’s jarring about red and blue? They’re my favourite colours?

Man that OC has jarring colors.

But at least they aren’t a red and black alicorn with heterochromia or something.