Pull git indicator colors out of theme

Co-Authored-By: Kay Simmons <kay@zed.dev>
Co-Authored-By: Mikayla Maki <mikayla@zed.dev>

styles/src/themes/common/base16.ts

@@ -113,6 +113,11 @@ export function createTheme(
       hovered: sample(ramps.blue, 0.1),
       active: sample(ramps.blue, 0.15),
     },
+    on500Ok: {
+      base: sample(ramps.green, 0.05),
+      hovered: sample(ramps.green, 0.1),
+      active: sample(ramps.green, 0.15)
+    }
   };
 
   const borderColor = {

styles/src/themes/common/theme.ts

@@ -78,6 +78,7 @@ export default interface Theme {
     // Hacks for elements on top of the editor
     on500: BackgroundColorSet;
     ok: BackgroundColorSet;
+    on500Ok: BackgroundColorSet;
     error: BackgroundColorSet;
     on500Error: BackgroundColorSet;
     warning: BackgroundColorSet;