i bought another 8gb memory ddr4 same as the old one but different color
This could very well be your problem.
RAM modules are ONLY guaranteed in the form sold (from the same pack) regardless as to the make / model / timings / voltages etc. This is because the manufacturing process changes frequently, so the 2 modules can never be guaranteed to work well with one another.
The "ensuring the specs are the same" is only a way of trying to
minimise risk, not eliminating it. And even then, you can buy 2 identical modules in spec, and they may not work together. Even if you tried the same modules in an identical system (same MB / CPU etc.). They may work on one, and not the other.
Not saying they never work, just it's a 50/50 gamble, sometimes they do, sometimes they don't, and this might be your case. It's why it's best practice to always buy a whole new pack when upgrading RAM.
Does each RAM module work individually by itself?
Have you verified it's not just the new module that is faulty?