While driving around,
I sometimes see a star on the outside wall of a house.

Sometimes the star is painted Gold,
which I understand as
“a Gold Star family lives here
we lost a child who died defending the USA”

But I see other colored stars.

Anyone know why their neighbors say why they have a non-gold star?

A Google search brings this up:

quote
Nowadays, some homeowners paint their stars,
as certain colors are believed to represent various meanings.
According to metalbarnstars.com,
black means protection,
blue means protection, peace, and calmness,
brown means earth and friendship,
green means growth and fertility,
orange means success in career,
red means emotion, passion, and creativity,
violet alludes to something sacred,
white represents the power of the moon,
and yellow means health.
Now ya know!
end quote

from

https://www.distractify.com/p/metal-star-on-house-meaning

or, the star hides a long structural bolt’s head:

https://dustyoldthing.com/metal-stars-old-houses/