excel themes

By way of adding to my suggestion that you tread carefully: I asked AI (ClaudeAI, specifically) what Excel pros have to say about the benefits and drawbacks of Excel themes. Here's the response. Notice that there are more concerns listed than positive, especially if this is a workbook that you'll be sending to other people.

The Positive Case

Consistency & Branding: Excel MVPs like Mynda Treacy and other professionals praise themes for maintaining corporate branding with one click. For dashboards and reports, themes can ensure uniform colors, fonts, and effects across entire workbooks, which is valuable for professional presentations.

Efficiency: Professionals appreciate that themes can transform a workbook's appearance quickly rather than manually formatting elements one by one. Custom themes can be saved and reused across all Office applications.

The Major Concerns

Portability Problems: This is the big one. As one commenter corrected on Mynda Treacy's site: when you send a file with a custom theme to someone outside your organization, the colors will change to "something completely off" and Excel substitutes default fonts even if the recipient has the fonts installed. The theme file itself doesn't travel with the document for external recipients.

Style Proliferation: Mynda Treacy warns that "Styles can breed like mice when copied from workbook to workbook and can quickly multiply to plague levels" — a colorful caution about how styles can create maintenance nightmares.

Version Compatibility: Users report frustration when Excel updates change default themes unexpectedly, breaking color-dependent macros and requiring manual theme resets on each new file.

Limited Adoption: Multiple sources note that few people actually use themes despite their availability. As one tutorial states, "few people use themes to enhance their worksheets" because Excel users focus on data rather than aesthetics.