button code

The button is grey probably because it is inactive. Check the isAccountPrimaryContactSet attribute. 

The correct code to add a button on a page

define("ContactPageV2", [], function() {
	return {
		entitySchemaName: "",
		attributes: {},
		modules: /**SCHEMA_MODULES*/{}/**SCHEMA_MODULES*/,
		details: /**SCHEMA_DETAILS*/{}/**SCHEMA_DETAILS*/,
		businessRules: /**SCHEMA_BUSINESS_RULES*/{}/**SCHEMA_BUSINESS_RULES*/,
		methods: {
			onOpenPrimaryContactClick: function() {
				// Determining the base contact Id.
				var primaryId = this.get("Account") ? this.get("Account").value : null;
				if (primaryId) {
					// Forming the address string.
					var requestUrl = "CardModuleV2/AccountPageV2/edit/" + primaryId;
					// Publishing a message and going to the
					// base contact edit page.
					this.sandbox.publish("PushHistoryState", {
						hash: requestUrl
					});
				}
			}
		},
		dataModels: /**SCHEMA_DATA_MODELS*/{}/**SCHEMA_DATA_MODELS*/,
		diff: /**SCHEMA_DIFF*/[
			{
				// Indicates that an operation of adding an item to the page is being executed.
				"operation": "insert",
				// Meta-name of the parent control item where the button is added.
				"parentName": "LeftContainer",
				// Indicates that the button is added to the control items collection
				// of the parent item (which name is specified in the parentName).
				"propertyName": "items",
				// Meta-name of the added button. .
				"name": "PrimaryContactButton",
				// Supplementary properties of the item.
				"values": {
					"style": Terrasoft.controls.ButtonEnums.style.BLUE,
					// Type of the added item is button.
					itemType: Terrasoft.ViewItemType.BUTTON,
					// Binding the button title to a localizable string of the schema.
					caption: "test",
					// Binding the button press handler method.
					click: {bindTo: "onOpenPrimaryContactClick"}
				}
			}
		]/**SCHEMA_DIFF*/
	};
});