diff --git a/src/ui/React/ThemeEditorModal.tsx b/src/ui/React/ThemeEditorModal.tsx
index 902a0a34c..299471e4e 100644
--- a/src/ui/React/ThemeEditorModal.tsx
+++ b/src/ui/React/ThemeEditorModal.tsx
@@ -46,6 +46,7 @@ function ColorEditor({ name, onColorChange, color, defaultColor }: IColorEditorP
                 deferred
                 value={color}
                 onChange={(newColor: Color) => onColorChange(name, "#" + newColor.hex)}
+                disableAlpha
               />
             </>
           ),