Are there any signs of a sociopath or psychopath before they show their true colors?

Time will only tell but you can also tell before time. Here are some signs they are a sociopath:

Manipulation: Pay close attention to Gas Lighting, Love Bombing or Framing to see if he manipulates using those things. It is the easiest way to find out that way since the other manipulation techniques can be a lot harder to tell.
School and Work: Sociopaths often have been known for bad behaviour in School or Work and find it hard to keep a job for long, this will make them often change jobs.
Impulsivity: Try insulting them, if they want to physically fight or react over aggressive it might be a sign of Sociopathy but can also be a sign of other Personality Disorders. A sociopath often wants to fight and get into physical fights and are very impulsive.

Now I have said a few things on how to see if someone is a sociopath but haven’t told you about psychopaths, unlike sociopaths they are very hard to tell but these might be signs they are a psychopath (and yes both aren’t the same):

Manipulation: Now a psychopaths manipulation is more complex and machievellian or cruel so you’ll have to pay attention whether all you do is in your or his favor. A psychopath often manipulates very well with it being hard to see if they do, though you can still try paying attention for Gas-lighting, Love Bombing or Framing.
Charm: Find yourself always around a person? Is the person perticularly popular or mysteriouse? It is a high chance it is a psychopath. Psychopaths usually are the most charming people in a room.
Pathological Lying: Psychopaths are almost always pathological liars, what does that mean now? It means they lie daily and it is normal for them to, pathological liars might use one of your own stories and make them seem like their one’s own.
Push and Pull: Let’s say you had a lot of good experience with a person but now they seem to ignore you and are completely distant, chances are they never liked you in the first place and just wanted to create an obsession by Love Bombing you first, ignoring you and then only giving you attention when you do something in his favor.

Narcissistic abuse