LED flickering and color not even

Hi

I'm having troubles with setting up my Hyperion + 172 WS2812b LED's + Arduino Uno R3.
For some reason I can't get a "stable" color (without flickering). Also when I set up a "static color" to display, it's not even. First part of the LED strip is brighter and has different HUE than rest of it.

Can this be the cause that I use 5V 3A power supply? Maybe something else?

Any help is highly appreciated!

Thanks!

Allright, thank you for your replies guys! Ordering a new power supply then. I'll keep this post updated once it gets here

Ok a small update. My new power supply is here and it helped a little bit but the color still wasn't even along whole stripe.
I was able to solve this by connecting end of the stripe to the power supply just like the beggining. Now all seems to be fine

One last thing that worries me a little bit is that color smoothing is not super fluid. It's a little bit choppy for a fracture of second.
My grabber frequency is set to 10.0HZ and smoothing updateFrequency to 25.0000. Is there anything else I can do?

Thanks for all previous replies!

Thanks for the reply. My baud rate is set to 460800 both in Arduino Sketch and Hyperion config, as that's the max value that my Arduino Uno R3 supports.