Conditionnal formating

[amouss]

Hello,

i can't have a background color when i make a conditional_formatting on a text :

style_ok = wb.styles.add_style(:bg_color => "002760", :fg_color => "FF428751", :type => :dxf )
style_ko = wb.styles.add_style(:bg_color => "ffe699", :fg_color => "FF0000", :type => :dxf )

    sheet.add_conditional_formatting("A1:B2", { :type => :containsText, :operator => :equal, :text => "A", :dxfId => style_ok, :priority => 1 })
    sheet.add_conditional_formatting("A1:B2", { :type => :containsText, :operator => :equal, :text => "B", :dxfId => style_ko, :priority => 1 }) 

Do i something bad or is it an issue ?

Thanks for ur help