So, to resolve this problem you don't need to create your package with a colon. You can do just packagename "mkdir spackagename" and then in your package.js in part Package.describe you can give full name with a colon.
// Short two-sentence summary.
summary: "The package is created for testing purposes only",
// Version number major-version:minor-version:patch-version
// Optional. Default is package directory name.
// Optional github URL to your source repository.
meteor create newpackage cdnewpackage
mkdir packages cd packages