Yes, you can use loops. Use a generic for loop to get all the parts in a model.

For Loop

This is a regular for loop.

for i = 1,10 do
    print("Boring.")
    wait()
end

Generic For Loop

This is a Generic For Loop. People use this for tables.

for i,v in pairs(workspace:GetChildren()) do
    print(i,v)
end

Final Product

local m = workspace.Model --Model here

for i,v in pairs(m:GetChildren()) do
    v.BrickColor = BrickColor.new("White") --Changes the brickcolor
end

Hope it helps!

Extra

If there are models inside of your model and inside of those models are parts that you need to edit use this script:

allowed = {
["Model"] = true,
["Folder"] = true,
["Configuration"] = true,
["Add more"] = true
}

function edit(m)
    for _,p in pairs(m:GetChildren()) do
        if p:IsA("BasePart") then
            p.BrickColor = BrickColor.White() --Change whatever.
        elseif allowed[p.ClassName] then
            edit(p)
        end
    end
end

edit(workspace.Model)

Rules

This is not a request site. If you don't ask detailed answers with a attempt of code, your question might get moderated as Not Constructive, meaning we can not build upon what you have provided us. If you do not know how to script well, check out this link for some great sources.

https://scriptinghelpers.org/questions/9539/#12184

Explanation

First off, you are on the right track with loops. All things in Datamodel, which is your game, has the GetChildren() function available to them.

GetChildren() will create a read-only list of objects inside the model or service.

The for loop will go through each object and perform a desired action. To set up our code, we will use;

for i,v in pairs() do

pairs() requires a table value inside the parenthesis. Essentially the script is reading, for everything in the table do something. That is where the GetChildren() function comes in.

for i,v in pairs(game.Workspace.Model:GetChildren()) do

Now even though GetChildren returns a read-only list, that only means you can not edit the list itself, but you can however edit the properties of the items inside the list.

for i,v in pairs(game.Workspace.Model:GetChildren()) do
    v.Name = 'Lol'
end

With every for, while, or if you need to have an end at the end of the statement. What the script is doing above is going, for everything in this table find the object and change the name to "Lol". The "i" in the loop means index, so it basically goes in order which typically for models and other objects it's what goes in first. Say a Player were to join and then another player, then another. The first player to join gets a index value of one, second player gets a index number of two, and so forth. "v" is the object in relation to those index values, hence the in pairs() function.

Remember, if this answer helped, do not forget to upvote it. If it answered your question, do not forget to hit that accept answer button to the right under my profile icon! Hope this helped.