gistfile1.rb

# ***config/application.rb***

module SpreeDemo
  class Application < Rails::Application
    # more awesome code here...
    
    config.to_prepare do |config|
      # more code here...
      
      config.autoload_paths += %W(#{config.root}/lib/spree/)
      
      #...
    end
    
  end
end

# ***lib/spree/bucket_configuration.rb***
module Spree
  class BucketConfiguration < Spree::Preferences::Configuration
    preference :bucket_name, :string, default: "waka"
    preference :bucket_url, :string, default: ""
  end
end

# ***config/initializers/bucket_configuration.rb***

module Spree
  SpreeDemo::Config = Spree::BucketConfiguration.new
end

SpreeDemo::Config[:bucket_name] = "blue_theme"
SpreeDemo::Config[:bucket_url] = "waka" + SpreeDemo::Config.bucket_name