Decoupling cap for self-powered LED matrix and LED strip Should I add a decoupling capacitor to my RGB 16x32 LED matrix powered directly via the 5V pin?

When I display a spectrogram, the current load is fluctuating quickly in the 100-250&nbsp;mA range (on average, the full range is 50-300&nbsp;mA).

If yes, which capacitor should I pick for this purpose?

I have 0.01&nbsp;&mu;F, 0.1&nbsp;&mu;F ceramic and 1&nbsp;&mu;F, 2.2&nbsp;&mu;F, 4.7&nbsp;&mu;F, 10&nbsp;&mu;F, 100&nbsp;&mu;F electrolytic caps.

EDIT: I'm also interested to know about this WS2812B LED strip i've connected to the 5&nbsp;V pin to another Arduino.

After reducing the brightness it has similar current consumption and fluctuation of the LED matrix.

In this tutorial they suggest to add a 1000&nbsp;&mu;F cap, but in my case the currents are much smaller.
No, there is no need. The matrix already has plenty of decoupling on it, including a large electrolytic for the incoming power and a small ceramic on each of the chips.