Can my HOA actually fine me for the color I painted my door?

Possibly, but the vagueness of "earth tones only" matters. Under Texas Property Code Chapter 202, an HOA may enforce deed restrictions, but restrictions must be reasonably interpreted. If the CC&Rs don't define "earth tones" or provide a color chart, your HOA's enforcement may be challengeable as arbitrary. Request a copy of any architectural guidelines or approved color palettes in writing. You can also dispute the fine through the HOA's internal dispute resolution process. Texas Property Code §209.007 requires HOAs to offer an opportunity to cure before fining and to follow due process. Consider attending the next board meeting and requesting a waiver.