Excel table colours changing when copied into email after recent update

Just wondering if anyone else is having a problem with their Excel table colours changing when copied into an email?

I have multiple workbooks I’ve used for years where the formatting has not changed. But about 3-4 weeks ago, I noticed the colours of the tables copied into emails changing. I use standard stock blue tables and now they appear purple or teal in outlook and gmail. It's affecting both my home and office PCs.

I’ve been using Ron de Bruin’s Excel-to-HTML copy/paste converter for years and this has never happened before. The problem persists if I copy/paste them manually.

Has anyone else run into this, or found a reliable workaround? I've tried using all the different themes and colour choices but no luck. I am on Office 365 on both machines; the office one is the standard subscription and my personal account is the insider version. Any suggestions much appreciated.