fastled ws2812 effect help

Hello, can anyone please help me with my project that i am trying to achieve, i have put way too many hours into this and will be willing to pay to achieve what i'm after.

My project started a while ago when i began with home automation. I am using a raspberry pi3 running home assistant witch has been working fine. My main aim was to have led strips that i can run different affects on, so i'm using a wemos d1 mini with a sketch on, and using mqtt to communicate and this has been working flawlessly.

The sketch i used was a modified version of Bruh Automations code by i really liked this code as it has a music visualiser mode and a lot of effects.

The thing that i'm after is to create a new affect that will work inside this sketch, so when i call the effect in home assistant it will run, but the effect must not loop.

The effect: lets say a led strip of 150 leds i'm wanting the leds to light up white one after the other but each led fades up as its climbing the strip, then when all leds are on it then fades from the white to a light blue without going off, ie R. G. B 0, 255, 255 and then stays their until something else is triggered, picture some sort of start up sequence. It would be a bonus if the effect could be modified on the fly as well like speed, brightness, colour etc.

I would also much appreciate any help/advice in helping me understand how i can include other effects in to this code, is it as simple as copy and past a different effect somewhere in this sketch? Their are a few great sketches out their but all have their different pros, like some have other effects i would like where others have not.

Any help on this would be fantastic.

Lots of examples in the FastLED library, some do stuff that's very close to what you want.

There's a function called "setcolor" or so that can set the colour for the whole strip in one go. Great for you when you are fading the R channel out.

Do mind that this many LEDs need a lot of power. Provide power to your strip at least on both ends, preferably a third power point in the middle.