SDL: visionOS: use black instead of white for the mouse overlay

SDL Commits
1 
From 7f7c1628cb38c9cc6936d88740cca709b754f016 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Mon, 18 May 2026 13:00:00 -0700
Subject: [PATCH] visionOS: use black instead of white for the mouse overlay

White is easier to see and people notice the overlay showing up when mouse input is enabled
---
 src/video/uikit/SDL_CurvedContentView.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/video/uikit/SDL_CurvedContentView.swift b/src/video/uikit/SDL_CurvedContentView.swift
index bbb7328093361..275a85f562ccc 100644
--- a/src/video/uikit/SDL_CurvedContentView.swift
+++ b/src/video/uikit/SDL_CurvedContentView.swift
@@ -167,7 +167,7 @@ internal struct SDL_CurvedContentView: View {
         .overlay {
             if mouseInputEnabled {
                 // This enables mouse motion events, but blocks hover location
-                Color.white
+                Color.black
                     .opacity(0.001)
                     .pointerStyle(.shape(Circle(), size: .zero))
             }