Visual Shader QOL: Improve vector port and icon colors

[Foyezes]

In VisualShader, the difference between Vector2 and Vector3 ports is a slight change of saturation in the color. This can be confusing sometimes.

The icon color for vec4 in the node search window doesn't match the port color.

If Vector2 and Vector3 icon and port colors were more distinguished, it'll be easier to tell them apart.