如何使用axlsx为包含数字的单元格更改字体颜色？

Question

这是一个使用axlsx gem创建简单工作簿的测试脚本。我试图循环行和单元格并将字体颜色更改为红色。但是，只有包含文本的单元格（即本例中的前两行）才会变为红色。包含数字的行保持默认的黑色。知道如何改变包含数字的单元格的颜色吗？

require 'axlsx'

Axlsx::Package.new do |p|
 p.workbook.add_worksheet(:name => "test") do |sheet|
        sheet.add_row ["First", "Second", "Third"]
        sheet.add_row ["First", "Second", "Third"]
        sheet.add_row [1, 2, 3]
        sheet.add_row [1, 2, 3]
        sheet.add_row [1, 2, 3]
        sheet.add_row [1, 2, 3]
        sheet.add_row [1, 2, 3]

        sheet.rows.each do |x|
            x.cells.each do |i| 
                i.color = "E8000"
            end
        end

  end
p.serialize('test.xlsx')
end