Hi Jess,
The Morning Doves leg will vary from a bright red to an orange in coloration, this isn't really associated with age but rather "genetic trait".
According to "standards" set upon the ring neck Dove, a bright red leg coloration is high standard.
Legs "should" be short and sturdy, bright red in color, free from feathers.
Here's a good link to help.
Mourning Dove Identify - projectwildbird.org