Choosing a Custom Color Scheme for Your Tooltips
Decide on a target color
Before editing anything, decide what you want tooltips to look like. A common approach is to match your resource pack or HUD theme, for example a soft blue, green, or gold. Write down the six-digit RGB color you want, then add the two-character alpha prefix in front of it to form the full ARGB string the mod expects.
Apply and verify
Open config/coloredtooltips-client.toml, replace the color value with your new ARGB string, save, and restart Minecraft. Hover over an item to confirm the change took effect. If nothing changed, the string is likely malformed; recheck that it contains only valid hex characters and the correct number of digits.
Keep it consistent
Because the mod recolors every tooltip rendered through Forge's tooltip code, one value controls item tooltips and GUI tooltips together. That means you cannot set a different color per item through this config alone, so choose a color that works across all of them. If you later want to revert, simply restore the original value or delete the config file and let the game regenerate it on the next launch. Always restart the game after editing, since the config is read at startup.