var colors = {red:0, blue:1, green:2};
var days = {sunday:0, monday:1, tuesday:2, wednesday:3, thursday:4, friday:5, saturday:6};

colors.red == days.sunday!

You can avoid mixing numbers with real values of the enum by using this:
var colors = {red:{}, blue:{}, green:{}};

This creates empty objects to use as enum values. They can only compare with themselves. They will never be equal to anything else, like value of another enum.