How to set up classes to match my scale?

[alaws-USGS]

I am trying to generate a color scale to match the following image:

I have the colors used for each but I have been unable to get the correct classes to return the proper color.

Does my number of classes need to be the # of scale values + 1?
Are class breaks inclusive of the class below or above? Ie if I want values of less than or equal to 5 to be blue, should I set the class break to 5.0001?

My variations

// # of classes = # of scales + 1
const scale = chroma.scale(["#CEBDA1", "#B5A378", "#9C8A50", "#837028", "#6A5700"]).classes([0, 0.001, 0.01, 0.1, 1, 10]);

// Shifting classes to the left but still 1 more class than scale (100 was chosen as it would be outside of range)
const scale = chroma.scale(["#CEBDA1", "#B5A378", "#9C8A50", "#837028", "#6A5700"]).classes([0.001, 0.01, 0.1, 1, 10, 100]);

// # of classes = # of scales
const scale = chroma.scale(["#CEBDA1", "#B5A378", "#9C8A50", "#837028", "#6A5700"]).classes([0.001, 0.01, 0.1, 1, 10]);

Any guidance you can give would be most welcome.