How to know the frequency from spectrogram image?

I would like to know the frequency from this spectrogram image. Can I know the frequency from the colorbar? Because I'm still confused of the colorbar unit. Is colorbar unit in Hz or dB? here's my code to get this image

p=dlmread('pv.txt'); m=mean(p); x=p-m; length(x); detik=24*60*60; fs=length(x)/detik; t=1/fs:1/fs:length(x)/fs; plot(t,x); Y=fft(x); plot(t,Y); f=fs*(0:length(Y)-1/length(Y)); spectrogram(x,128,120,256,fs,'yaxis');

I'm looking forward your help, thank you Frely

[KSSV]

What are the units of x?

Answer 1

[Christoph F.]

The frequency is plottet on the vertical (y-) axis.

The color indicates amplitude, so it's probably in dB.