Thanks for reaching out here in the community.
Google Nest thermostats are designed to work with most 24 V systems, even older systems. They work with all common fuel types including natural gas, oil, and electricity.
Also, we should be able to tell further if you can take a clearer photo showing the wire labels or you could write in your reply what the wire labels are.
I hope to hear from you soon.
We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community.