Properties 'bg' inconsistent result based on values

[sabbir-anwar]

I'm using UMLet version 15.1. properties 'bg' is not consistent with the values. I have given the bg properties value '1', it showed black background color. It doesn't show any "Invalid value" error.

Steps:
select a figure -> go to properties -> write "bg=1"

Result:
Background of the figure becomes black

Steps:
select a figure -> go to properties -> write "bg=11111"

Result:
Background of the figure becomes blue