<mx:HBox id="headerContent"
                 width="100%" height="{headerGroup.height - 45}"
                 backgroundAlpha="{getStyle('contentBackgroundAlpha')}"
                 backgroundColor="{getStyle('contentBackgroundColor')}".HeaderStyle
{
    background-color: #FFFF00; // default Color 
}In config.xml,<style> <colors>0x4C2600,0xFFEDB8,0xB2AD81,0x6F6750,0x4C2600,0xFFFFFF,0xFFFF00</colors> <alpha>0.8</alpha> </style>Below is the Code from UIManager.as that you will need to modify.
.
.
.
        var titleFontName:String = (configData.titleFont.name != "") ? configData.titleFont.name : defaultFontName;
        var titleFontSize:int = (configData.titleFont.size != 0) ? configData.titleFont.size : 20;
        var fontName:String = (configData.font.name != "") ? configData.font.name : defaultFontName;
        var fontSize:int = (configData.font.size != 0) ? configData.font.size : defaultFontSize;
        
        var headerBackGroundColor:uint; //My Code
        
        styleAlpha = configData.styleAlpha;
        if (numberOfStyleColors > 4)
        {
            textColor = configData.styleColors[0];
            backgroundColor = configData.styleColors[1];
            rolloverColor = configData.styleColors[2];
            selectionColor = configData.styleColors[3];
            titleColor = configData.styleColors[4];
            applicationBackgroundColor = (configData.styleColors[5] != null) ? configData.styleColors[5] : 0xFFFFFF;
            
            headerBackGroundColor = configData.styleColors[6]; //My Code
        }
       
.
.
.
        cssStyleDeclarationBannerTitle.setStyle("fontFamily", titleFontName);
        topLevelStyleManager.setStyleDeclaration(".BannerTitle", cssStyleDeclarationBannerTitle, false);
        //My Code Start
        var cssStyleDeclarationHeaderStyle:CSSStyleDeclaration =  topLevelStyleManager.getStyleDeclaration(".HeaderStyle");
        
        if (numberOfStyleColors > 4)
        {
            cssStyleDeclarationHeaderStyle.setStyle("backgroundColor", headerBackGroundColor);
        }
        topLevelStyleManager.setStyleDeclaration(".HeaderStyle", cssStyleDeclarationHeaderStyle, false);
        // My Code End
        
        var cssStyleDeclarationBannerSubtitle:CSSStyleDeclaration = new CSSStyleDeclaration(".BannerSubtitle");
        if (numberOfStyleColors > 4)
        {
            cssStyleDeclarationBannerSubtitle.setStyle("color", titleColor);
        }
        topLevelStyleManager.setStyleDeclaration(".BannerSubtitle", cssStyleDeclarationBannerSubtitle, false);
      
Hope this helps.
					
				
			
			
				
			
			
				
			
			
			
			
			
			
		Since this change is for the Header controller only, I suggest making changes to headercontroller widget only. but
See Coordinates widget source.
If you still want it through main config file, you will have to make following changes:
You will have to perform following:
In defaults.css,
add:.HeaderStyle { background-color: #FFFF00; // default Color }In config.xml,
add the seventh color e.g. 0xFFFF00 (yellow) first six are used elsewhere.
e.g.<style> <colors>0x4C2600,0xFFEDB8,0xB2AD81,0x6F6750,0x4C2600,0xFFFFFF,0xFFFF00</colors> <alpha>0.8</alpha> </style>Below is the Code from UIManager.as that you will need to modify.
Add the lines that has comment "My Code" or "My Code Start". . . var titleFontName:String = (configData.titleFont.name != "") ? configData.titleFont.name : defaultFontName; var titleFontSize:int = (configData.titleFont.size != 0) ? configData.titleFont.size : 20; var fontName:String = (configData.font.name != "") ? configData.font.name : defaultFontName; var fontSize:int = (configData.font.size != 0) ? configData.font.size : defaultFontSize; var headerBackGroundColor:uint; //My Code styleAlpha = configData.styleAlpha; if (numberOfStyleColors > 4) { textColor = configData.styleColors[0]; backgroundColor = configData.styleColors[1]; rolloverColor = configData.styleColors[2]; selectionColor = configData.styleColors[3]; titleColor = configData.styleColors[4]; applicationBackgroundColor = (configData.styleColors[5] != null) ? configData.styleColors[5] : 0xFFFFFF; headerBackGroundColor = configData.styleColors[6]; //My Code } . . . cssStyleDeclarationBannerTitle.setStyle("fontFamily", titleFontName); topLevelStyleManager.setStyleDeclaration(".BannerTitle", cssStyleDeclarationBannerTitle, false); //My Code Start var cssStyleDeclarationHeaderStyle:CSSStyleDeclaration = topLevelStyleManager.getStyleDeclaration(".HeaderStyle"); if (numberOfStyleColors > 4) { cssStyleDeclarationHeaderStyle.setStyle("backgroundColor", headerBackGroundColor); } topLevelStyleManager.setStyleDeclaration(".HeaderStyle", cssStyleDeclarationHeaderStyle, false); // My Code End var cssStyleDeclarationBannerSubtitle:CSSStyleDeclaration = new CSSStyleDeclaration(".BannerSubtitle"); if (numberOfStyleColors > 4) { cssStyleDeclarationBannerSubtitle.setStyle("color", titleColor); } topLevelStyleManager.setStyleDeclaration(".BannerSubtitle", cssStyleDeclarationBannerSubtitle, false);Hope this helps.