Q: Proud owner but colourblind!  How long is the charging period?

The manual (if the shuffle is the current 4th gen)

http://manuals.info.apple.com/en_US/iPod_shuffle_4thgen_User_Guide.pdf

says, "The battery is 80-percent charged in about two hours and fully charged in about three hours." (page 10)

Also, the VoiceOver feature is supposed to provide an audible battery status message (over the headphones), when you press the VoiceOver button twice.  (page 11)

Pressing the button twice is only the command to hear the battery status.  It does not enable the VoiceOver feature.  This actticle explains how to enable and use VoiceOver on the 4th gen shuffle

http://support.apple.com/kb/HT4322

Hopefully, it will work properly after you set it up.  VoiceOver can audibly tell you many other things besides just the battery status.  On a shuffle, it replaces having a screen.