How to create a graph from measurement matrix with custom colormap?

Hello,

First off: I´m not a Matlab expert, I´ve mostly taught it myself. I need those diagrams for my thesis and couldn´t solve it myself so far by looking in the internet.

I´ve been trying a lot to figure out the following problem:

I want to create a graph from a interpolated matrix with a custom colormap of values which have been measured; each measurement can be identified by its position (similar to a chess board, e.g. E3 or F4).

To get the data into Matlab and interpolate it I use this:

dataX=graphX('random_measurements.xlsx');
ValuesX=dataX(36:42,2:7);
ValuesX=cell2mat(ValuesX);
[xx yy] = meshgrid(1:0.1:9);  %force it to interpolate at every 10th pixel
Xneu=interp2(ValuesX,xx,yy)

From that i can create 2 diagrams, one with the raw measurements, one interpolated.

figure()
surf(Xneu)
figure()
surf(ValuesX)

It´s visible that in the interpolated graph I get empty fields where the graph should already be done. How can I make it look neat?

Confusing me is that both the graphs seem to be inverted in comparison to the excel diagram below. Did I do some conversion mistake?

Related to the last issue how can I then add the annotation of the axis? I´ve already tried

set(gca,'YTickLabel',{'A';'B';'C';'D';'E';'F';'G'})
set(gca,'XTickLabel',{'7';'6';'5';'4';'3';'2'})

Is there any more elegant way imorting it from the excel?

And finally: How can I make the colorbar in those diagrams go from 0 = green to [defined value]=red. Ideally the colour change would be going in both directions (+z and -z going from 0 = green to red). I´ve already experimented with "custom colormap" and "rgb", which I didn´t manage to make it work.

Thanks in advance for any help. It will be greatly appreciated!