fix source_color default value

servers/rendering/renderer_rd/storage_rd/material_storage.cpp

@@ -344,7 +344,7 @@ static void _fill_std140_variant_ubo_value(ShaderLanguage::DataType type, int p_
 	}
 }
 
-_FORCE_INLINE_ static void _fill_std140_ubo_value(ShaderLanguage::DataType type, const Vector<ShaderLanguage::Scalar> &value, uint8_t *data) {
+_FORCE_INLINE_ static void _fill_std140_ubo_value(ShaderLanguage::DataType type, const Vector<ShaderLanguage::Scalar> &value, uint8_t *data, bool p_use_linear_color) {
 	switch (type) {
 		case ShaderLanguage::TYPE_BOOL: {
 			uint32_t *gui = (uint32_t *)data;
@@ -441,18 +441,28 @@ _FORCE_INLINE_ static void _fill_std140_ubo_value(ShaderLanguage::DataType type,
 
 		} break;
 		case ShaderLanguage::TYPE_VEC3: {
+			Color c = Color(value[0].real, value[1].real, value[2].real);
+			if (p_use_linear_color) {
+				c = c.srgb_to_linear();
+			}
+
 			float *gui = reinterpret_cast<float *>(data);
 
 			for (int i = 0; i < 3; i++) {
-				gui[i] = value[i].real;
+				gui[i] = c.components[i];
 			}
 
 		} break;
 		case ShaderLanguage::TYPE_VEC4: {
+			Color c = Color(value[0].real, value[1].real, value[2].real, value[3].real);
+			if (p_use_linear_color) {
+				c = c.srgb_to_linear();
+			}
+
 			float *gui = reinterpret_cast<float *>(data);
 
 			for (int i = 0; i < 4; i++) {
-				gui[i] = value[i].real;
+				gui[i] = c.components[i];
 			}
 		} break;
 		case ShaderLanguage::TYPE_MAT2: {
@@ -786,7 +796,7 @@ void MaterialStorage::MaterialData::update_uniform_buffer(const HashMap<StringNa
 
 		} else if (E.value.default_value.size()) {
 			//default value
-			_fill_std140_ubo_value(E.value.type, E.value.default_value, data);
+			_fill_std140_ubo_value(E.value.type, E.value.default_value, data, p_use_linear_color);
 			//value=E.value.default_value;
 		} else {
 			//zero because it was not provided