You're running into a common quirk with these systems. Most people who get that same reset issue find it's because they saved the cyan gradient as a temporary scene rather than a permanent 'lock' or 'static' mode. The app defaults to cycling through scenes when it initializes, which is why your custom color keeps snapping back to a default or moving to a diferent preset. I figured this out when setting up a similar setup in my own living space. Instead of just applying the color, you need to look for a function usually labeled 'Lock Scene' or 'Commit Setting' inside the deeper menu, not the quick-access color wheel. If the OmniGlow app doesn't explicitly label it 'Lock,' try setting the color, then finding a 'Save as Preset' option, and then looking for an option to disable the automated color shifting for that specific preset.
If the app interface is being intentionally vague, the other method is to ensure that the light controller is set to manual mode rather than 'Automation' or 'Dynamic.' Once it is in manual mode, the static color should hold even if the app refreshes. This essentially tells the device to hold the exact RGB value you entered without trying to run any programmed sequence. It’s just a toggle switch, but it does a huge difference in stability.
It’s annoying when you spend time tweaking a color wheel only for it to reset when you check the app later. Hopefully, finding that lock or manual setting solves the whole fiddling problem for you.