While God is beyond colours, people have chosen certain
colours to represent their connection with God or their
idea of God.   (Some) priests, spiritual teachers,
meditation teachers have chosen certain colours for their
clothes and perhaps even other things.

Catholic priests wear black garment (cassock), Buddhist robes
can be orange or brown, some spiritual/meditation schools and
retreats use different colour T-shirts or shirts to distinguish
among the different teacher levels.

Colours are not just pretty things to look at.
They can have beneficial or detrimental effect on people.
Generally, some colour are associated with a calming effect
and some colours represent action, even aggression.
Light blue, for example, has a calming effect (unless it is
the person's "bad" colour); red colour is associated
with action, even anger and aggression (unless it's the person's
"good" colour).   White colour is considered neutral.
Black is the best to avoid for clothes, cars, decor, houses;
it can contribute to susceptible people being blocked, stuck
in black (rather than being in light).

It is very very important that priests, spiritual teachers,
meditation teachers, life coaches choose to wear colours that
are the most likely to be beneficial to people (at least as the top
visible layer; the below-layer best be the teacher's "good" colour
if different from the top layer colour; for example, if the teacher's
"good" colour is red, it can be worn below the top layer).
A person looking at a priest or teacher may get subconsciously
put off or weakened by the colour of the teacher's or priest's clothes.
The poorest choice of colour is black and red; white can be included, too.
Black is downright detrimental to people who are spiritually weak,
energetically depleted and fragmented, which is most people.
Even a relatively small black surface can contribute to spiritual
stuckness, lack of awareness, and weaken the person (hearing about God
is one thing, but being able to accept God requires certain wholeness
and spiritual strength).   When the priest/teacher wears black,
the listener hears one thing, and at the same time gets a conflicting
visual message: the ears hear about God, and the eyes see darkness...what
the heck?   For higher energized people black can be OK, as in
neutral, but even then it doesn't contribute positively, so what's the point?
Why does a person of Light need an association with blackness when
there are so many other colours...vibrant colours?
People who experience NDE (near death experience), high states of
consciousness, or enlightenment talk about experiencing Light,
luminosity so beautiful...beyond description - not black nor darkness.

The catholic priest gets a tripple whammy with a bonus:
- they are not necessarily higher energized people
- they wear black
- they are unnaturally forced to celibacy
- bonus: parts of the Bible are non-integrous (negative, non-life
        supporting)
No wonder there have been so many negative issues...

While red colour is beneficial to people who have it as their
"good" colour, it is not really beneficial to others.
It's associated with anger, action, aggression.   If a person
has subconscious issues such as anger and hyperactivity, red colour
could make it worse.   Most people have a lot of subconscious
anger, especially if they ingest toxins such as alcohol, coffee,
drugs medical and recreational.   Toxins can also "spin"
the person's energy into an unhealthy overdrive.   Red colour
can make this worse.
Can you imagine what would happen if doctor offices and prison cells
would be painted red?

White colour is neutral.   It's a sterile colour, having
no vibrancy.   It can have its uses, but for priest's/teacher's
clothes...hmm...what's the point?   Priests/teachers should
inspire, not sterilize.

Probably the safest colours are purple, blue, yellow.
Yes, if one of them is someone's "bad" colour,
it can weaken the person.   However, overall they seem like
benign colours and are generally regarded as beneficial.

Please visit this page for more info about your "good"
and "bad" colour.