The recommended way to manage conditional formatting is via Worksheet#add_conditional_formatting
Conditional formatting allows styling of ranges based on functions
Creates a new Axlsx::ConditionalFormatting object
Add a ConditionalFormattingRule. If a hash of options is passed in create a rule on the fly.
be already created Axlsx::ConditionalFormattingRule elements or hashes of options for automatic creation. If rules is a hash instead of an array, assume only one rule being added.
Rules to apply the formatting to. Can be either a hash of options to create a Axlsx::ConditionalFormattingRule, an array of hashes for multiple ConditionalFormattingRules, or an array of already created ConditionalFormattingRules.
Range over which the formatting is applied, in “A1:B2” format
Serializes the conditional formatting element