Hi. Welcome. Thank you for sharing your map work. The land surfaces look nice in roughness and colors. The sea color is too bright for me, like you said, you are going to change it. Ok, now some constructive feedback. I do not think it is orthographic projection. Orthographic shows the world as viewed from space, so, you see one side of the world, and it looks round. Also on orthographic projection (and many map projection types) your graticule (grid of latitude and longitude) would be curved. Your grid appears square. So study about "map projections" to learn some things that can help make this better and help you understand the size, shape, distances of your world surface. A related thought: you are showing part of the world, not the whole world, on this map. If it was the whole world (on a round globe world) any land crossing an edge would continue on the other side. For example your continent at the top goes off the top edge but where does it continue? That is why this is a large regional map, something less than entire world.

Next also study about rivers, how they flow (downhill). Some of your rivers look nice (such as the river on the southwest side of central continent, and, what looks like a dried riverbed or muddy river on the southeast side of same central continent). Some of your rivers are confusing, and need work, such as the river complex in the white snowy area, top left of same central continent. Here the river makes an unexpected X shape.

Good luck with your map work. Please post again.