Is it possible to define colormap ranges or merge colormaps?

I am creating a heat map using imagesc with data in [0 100]. I need to emphasize two data ranges as distinct, say [0 5] shades of red and [5 100] colors that are not red.

I'm a proficient MATLAB user/googler generally, but am not sure what vocabulary to use when searching. Any advice - either tips on how to accomplish this or terms to google - would be welcome!

Thanks!

Answer 1

[Chad Greene]

Try concatenating colormaps, like this. Below I'm using my cmocean colormaps, which are available on File Exchange, but you can concatenate any RGB arrays.

% Some data 
Z = abs(peaks(500));
Z = 100*Z/max(Z(:)); % scaled 0 to 100

figure
imagesc(Z) 
cb = colorbar; 

% Two colormaps: 
col1 = cmocean('amp',6); % 6 shades of red
col2 = parula(95);       % 95 shades of parula

% Concatenate colormaps: 
col = cat(1,col1,col2); 
colormap(col)

[lstr]

Thank you so much! This was exactlly what I was looking for!