### 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 (completion_function == builtin_func_defs[idx].name) {
					if (builtin_func_defs[idx].tag != completion_class) {
						idx++;
						continue;
					}
					if (calltip.length()) {
						calltip += "\n";
					}
					calltip += get_datatype_name(builtin_func_defs[idx].rettype);
					calltip += " ";
					calltip += builtin_func_defs[idx].name;
					calltip += "(";
					bool found_arg = false;
					for (int i = 0; i < BuiltinFuncDef::MAX_ARGS - 1; i++) {
						if (builtin_func_defs[idx].args[i] == TYPE_VOID) {
							break;
						}
						if (i > 0) {
							calltip += ", ";
						} else {
							calltip += " ";
						}
						if (i == completion_argument) {
							calltip += char32_t(0xFFFF);
						}
						if (out_args.has(i)) {
							calltip += "out ";
						}
						calltip += get_datatype_name(builtin_func_defs[idx].args[i]);
						String arg_name = (String)builtin_func_defs[idx].args_names[i];