TechMon+Amarok is software that can monitor system parameters and has a theme that is focused on temperature. However, the edited version of the theme removes the temperature sensor feature.
This version also has some additional tweaks compared to the standard TechMon theme, such as exclusively using a dark theme. If you want black headers text to display your CPU, HDD, and other information, then this theme is the one you need.
To run this software, you'll need SuperKaramba. However, once you have that installed, it's easy to get started with TechMon + Amarok without sensors (temp) and customize it to your liking.