### 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)

op->arguments.write[0] = _reduce_expression(p_block, op->arguments[0]);
		if (op->arguments[0]->type == Node::NODE_TYPE_CONSTANT) {
			ConstantNode *cn = static_cast<ConstantNode *>(op->arguments[0]);
			DataType base = get_scalar_type(cn->datatype);
			Vector<ConstantNode::Value> values;
			for (int i = 0; i < cn->values.size(); i++) {
				ConstantNode::Value nv;
				switch (base) {
					case TYPE_BOOL: {
						nv.boolean = !cn->values[i].boolean;
					} break;
					case TYPE_INT: {
						nv.sint = -cn->values[i].sint;
					} break;
					case TYPE_UINT: {
						
						nv.uint = 0 - cn->values[i].uint;
					} break;
					case TYPE_FLOAT: {
						nv.real = -cn->values[i].real;
					} break;
					default: {
					}
				}
				values.push_back(nv);
			}
			cn->values = values;
			return cn;
		}
	}