Examples: Use color management in lightmap example. (#26018)

* Examples: Use color management in lightmap example.

* Update lightmap.json

examples/webgl_materials_lightmap.html

@@ -34,8 +34,6 @@
 			import { MeshBasicNodeMaterial, vec4, color, positionLocal, mix } from 'three/nodes';
 			import { nodeFrame } from 'three/addons/renderers/webgl/nodes/WebGLNodes.js';
 
-			THREE.ColorManagement.enabled = false; // TODO: Consider enabling color management.
-
 			let container, stats;
 			let camera, scene, renderer;
 
@@ -59,7 +57,7 @@
 
 				// LIGHTS
 
-				const light = new THREE.DirectionalLight( 0xaabbff, 0.3 );
+				const light = new THREE.DirectionalLight( 0xd5deff, 0.3 );
 				light.position.x = 300;
 				light.position.y = 250;
 				light.position.z = - 500;
@@ -67,8 +65,8 @@
 
 				// SKYDOME
 
-				const topColor = new THREE.Color().copy( light.color ).convertSRGBToLinear();
-				const bottomColor = new THREE.Color( 0xffffff ).convertSRGBToLinear();
+				const topColor = new THREE.Color().copy( light.color );
+				const bottomColor = new THREE.Color( 0xffffff );
 				const offset = 400;
 				const exponent = 0.6;