Material Overrides allow you to edit materials inside complex/deep mesh structures like SVGs or Text. This can be achieved via the Sub-Mesh Behaviour's Fill or Stroke tabs.
The Swap Color Override enables you to take one specific color within a Sub-Mesh (e.g. an SVG, Text Shape or Duplicator) and swap it for another one.
​Common Attributes + ​
Old Color - set the color you want to swap.
New Color - set the color you want to swap to Old Color to.
Import an SVG into the Assets Window.
Drag it in to the Viewport to create an SVG Shape.
Connect a Sub Mesh to the Deformer attribute of the SVG Shape.
On the Sub Mesh, switch to the Fill tab in the Attribute Editor.
Use the +
button to add a Swap Color to the Fill Overrides attribute.
Set a value for Old Color that matches one in the SVG.
Set a value for New Color to swap Old Color to.