[SalesForce] Map of string and list of integer with apex repeat in visualforce page

I do not see examples of exactly what you want in documentation such as Building a Complex Chart with Visualforce Charting.

But you should be able to get part of the way there because apex:barSeries supports colorSet and colorsProgressWithinSeries attributes. It looks like putting the colors there using a true value should give a different color per bar.

In the examples I have seen, the apex:legend is typically used to describe the series and you only have one series (your apex:barSeries). You are trying to get the legend to repeat the labels of the x-axis and that does not appear to be a supported option.

So I suggest the compromise of using the colored bars and just removing the legend.

PS

The code below produces the chart below and demonstrates that just setting colorsProgressWithinSeries allows the colors from the apex:chart to be used. When experimenting with the size of the chart, I found that the legends are hidden when they don't fit so making the chart bigger is the simplest way to get all the legends shown. One purpose of the legend when displayed is to turn a series on and off so the legend has little value when there is only one series. And there appears to be no option to repurpose the legend to show axis values instead so I think your are out of luck. (Or if the first chart you show was created using apex:chart contact whoever created it and ask them.)

<apex:page controller="ChartController">
    <apex:pageBlock title="Annual Recurring Revenue">
        <apex:chart name="AnnualRecurringRevenue" data="{!nvs}" width="400" height="400"
                colorSet="#156F9E,#FF9123,#6BAE4A,#424242,#A4A4A4">
            <apex:axis type="Numeric" position="left" grid="true" title="$(Millions)"
                    fields="v"/>
            <apex:axis type="Category" position="bottom" grid="false" title="Quarter"
                    fields="n"/>
            <apex:barSeries orientation="vertical" axis="left" xField="n" yField="v"
                    colorsProgressWithinSeries="true"/>
        </apex:chart>
    </apex:pageBlock>
</apex:page>

public class ChartController {
    public class Nv {
        public String n { get; private set; }        
        public Decimal v { get; private set; }
        Nv(String n, Decimal v) {
            this.n = n;
            this.v = v;       
        }
    }
    public Nv[] getNvs() {
        return new Nv[] {
            new Nv('Actual', 106.00),
            new Nv('Forecast', 150.56),
            new Nv('Plan', 135.00),
            new Nv('Prior Qtr', 97.00),
            new Nv('Prior Yr', 88.44)
        };
    }
}

This controller:

public class MyController {
    public Map<String, List<String>> myMap {
        get {
            return new Map<String, List<String>>{
                    'abc' => new List<String>{'123', '456'},
                    'def' => new List<String>{'654', '321'}
                    };
        }
    }
}

and page:

<apex:page controller="MyController">
    <apex:repeat value="{!myMap}" var="key">
        <apex:pageBlock >
            <apex:pageBlockTable value="{!myMap[key]}" var="listItem">
                <apex:column value="{!listItem}"/>
            </apex:pageBlockTable>
        </apex:pageBlock>
    </apex:repeat>
</apex:page>

produces the expected repeated page block tables (as the apex:repeat automatically iterates over the map keys).

So I think your problem lies in the code that builds myMap or in the code that exposes it from your controller and you have not posted that code.