Update TS types in definition file

Use the full words for parameters in color methods, not just
`r` and `g`. This make our definitions more self-documented and
allow us to remove @param from comments. This commit also fix
other minor issues.

package.json

@@ -61,8 +61,7 @@
 	"types": "index.d.ts",
 	"xo": {
 		"ignores": [
-			"test/_flow.js",
-			"*.ts"
+			"test/_flow.js"
 		]
 	}
 }