Disable HTML in emails

I have a dark website, yesterday someone told me that their emails came out dark too which means they can't print them (or won't).
I thought I saw somewhere where I could disable HTML emails and just send plain text - is that possible?
Otherwise is there a print css file I should use?
Thanks Tuan!

Hi

Unfortunately, we could not use plain text email in this case because the email messages contains HTML code. Maybe you can forward me a sample email so that I can check it for you ?

Tuan

No worries Tuan - I know it's my fault for changing the colour of the table that shows the different events without checking the effect on email. I can change it to something lighter.
I don't really like dark websites myself but the client insisted. :whistle:
Also I have resolved the problem I was having with Paypal and SSL - the client in that case hadn't validated his new Paypal account!!
Would be so much easier without clients.....

That's great ! Thanks for letting me know !

Tuan