### Godot version

v4.1.dev.custom_build.a7276f1ce

### System information

Win10, AMD 2600, GeForce GTX 1060, Vulkan API 1.3.205

### Issue description

I can't get correct color data from an array of source_color type.
The color data is saved as **Color** in the file:
`shader_parameter/palette = [Color (1, 0, 0, 1), Color (0, 1, 0, 1), Color (0, 0, 1, 1)]`
Shouldn't it be saved as PackedColorArray?


### Steps to reproduce

1.Declare an array of source_color type.
2.Set colors.

### Minimal reproduction project

[shadertest.zip](https://github.com/godotengine/godot/files/11246504/shadertest.zip)

if (tk.type != TK_PARENTHESIS_CLOSE) {
				_set_error(RTR("Expected ')' in expression."));
				return nullptr;
			}
		} else if (tk.type == TK_FLOAT_CONSTANT) {
			ConstantNode *constant = alloc_node<ConstantNode>();
			ConstantNode::Value v;
			v.real = tk.constant;
			constant->values.push_back(v);
			constant->datatype = TYPE_FLOAT;
			expr = constant;
		} else if (tk.type == TK_INT_CONSTANT) {
			ConstantNode *constant = alloc_node<ConstantNode>();
			ConstantNode::Value v;
			v.sint = tk.constant;
			constant->values.push_back(v);
			constant->datatype = TYPE_INT;
			expr = constant;
		} else if (tk.type == TK_UINT_CONSTANT) {
			ConstantNode *constant = alloc_node<ConstantNode>();
			ConstantNode::Value v;
			v.uint = tk.constant;
			constant->values.push_back(v);
			constant->datatype = TYPE_UINT;
			expr = constant;
		} else if (tk.type == TK_TRUE) {
			
			ConstantNode *constant = alloc_node<ConstantNode>();
			ConstantNode::Value v;
			v.boolean = true;