Using Replcation on my program the replicated does not get color. why?

What i am doing is, from a class that only spawn things when its the server.
I Spawns Cubes as a specific Blueprint.
It shows it and when something moves it moves too but.
the colors are NOT being replicated nor some special information it should have and i cannot understand why.
Is not enough to explain I want to replicate or i just need to tell it that anything that changes it should be send over?
Really need help, I tried to read all whats relvant but none of it is made on C++, and now i cannot change what i am doing and use blueprints for everything.
also some functions are normal but some functions are not the same on C++ than on blueprints so makes learning far harder.
I need t present this in 2 day tops finished and i have no idea how to do the multipleyer part. please hurry to answer.

To explain it a bit better i did the following:

  1. have an actor that spawn other actors. (in that one i manage to only do it if its the server to not have duplication).
  2. Make class Cube and a Blueprint BPCube, and marked that blue print to be replicated always. and also movement.
  3. When i spawn the items they start white, then the same function that spawn them calls the object to change its color.
    This part the 3 works perfectly on the server but does not on the replication,why not? should the server do something else?
    should the cube do something else? is not this automated because its being replicated?
    Also tried to put keyworkds like (Replicated) to the variable that is in charge of doing the coloring. but then a syntax error happens.
    Or may be i should put the Cube Bluprint not as actor but as something else? or to inherit also from some other place or be inside some other?
    really cannot found any decent documentation on this that does not use blueprints for everything (thing i cannot do at this point).

either the color change function needs to be multicast to notify all clients of the color change,
or the color variable needs to be replicated and you need to react to the color change OnRepNotify