diff --git a/src/platform/packages/shared/kbn-palettes/classes/palettes.ts b/src/platform/packages/shared/kbn-palettes/classes/palettes.ts
index 8b0ea42dd0724..00895776007e4 100644
--- a/src/platform/packages/shared/kbn-palettes/classes/palettes.ts
+++ b/src/platform/packages/shared/kbn-palettes/classes/palettes.ts
@@ -37,7 +37,7 @@ export class KbnPalettes {
 function buildAliasMappings(palettes: IKbnPalette[]): Map<string, string> {
   return palettes.reduce((acc, { id, aliases }) => {
     aliases.forEach((alias) => {
-      acc.set(alias, id);
+      if (!acc.has(alias)) acc.set(alias, id);
     });
     return acc;
   }, new Map());
diff --git a/src/platform/packages/shared/kbn-palettes/palettes/categorical/elastic.ts b/src/platform/packages/shared/kbn-palettes/palettes/categorical/elastic.ts
index 0ed2d26d1b939..15c374bf1fd88 100644
--- a/src/platform/packages/shared/kbn-palettes/palettes/categorical/elastic.ts
+++ b/src/platform/packages/shared/kbn-palettes/palettes/categorical/elastic.ts
@@ -20,6 +20,7 @@ export const elasticPalette = new KbnColorFnPalette({
   id: KbnPalette.Default,
   type: 'categorical',
   aliases: [
+    KbnPalette.Default, // needed when switching between new and old themes
     'elastic_borealis', // placeholder - not yet used
     KbnPalette.Amsterdam, // to assign to existing default palettes
   ],