In the simplest, Razer Synapse 3 interface states, next to the settings for lighting, "Quick effects are presets that can besaved to a device's profile and synced with other supported Razer Chroma-enabled devices".
So far, according to personal experience, I can testify that the BlackWidow Elite (2020.08) RGB keyboard, which allows 4 on-board memory profiles, and the Basilisk V2 (2021.11) Wired RGB mouse, which allows 4 on-board memory profiles and 1 hybrid profile (for latest used profile), still do not save Lighting Quick Effects (E.g. single static colour) to any on-board memory by Razer Synapse 3 of various versions that are released during 2020.08-2021.11 (up to version 3.6.1130.111217).
Surprisingly oddly, the DeathAdder Essential (2019.02) non-RGB mouse, which allows none on-board memory profiles, does maintain a predetermined brightness level with the static effect for the green lighting after Razer Synapse 3 and all its relevant services have been fully exited (verified in Windows Task Manager and Services).
I shall spare any further lengthy criticism here, for the problem has been evidently obvious for years with countless users. Just hoping more resonating users would second the situation and the second the request, so that Razer can resolve responsibly accordingly (i.e. do what you say, or just do not say what you do not do) sooner than later.
Thanks.
An ardent user