Welcome to home ownership! Also welcome to the "well, I originally wanted to wait 5 years but I guess now is as a good time as any because [reason]" club.
You've already identified the most "pressing" wants:
The "main" outdoor lights like porch lights and patio lights, IMO, shouldn't need to be colour-changing since they're there to provide, well, light, rather than ambiance. Also, from a (still relatively) new homeowner's viewpoint, be wary of spending too much on the smarts now because you'll inevitably find yourself having to spend money for random emergency upkeep things. It's fun.
Anyway, that aside, for outside lights, I'd go with regular bright-as-you-can-get white LEDs but put the switch for the lights on Caseta. They're pretty pricey but damn dead reliable and always work. Speaking of, which ecosystem are you planning on using? That should, honestly, be the first thing you decide because there are some considerations with it. I personally use HomeKit because it's very much privacy oriented and all commands are local so even if there's an internet outage, I can still control my devices inside the house. That said, overall compatibility is slowly becoming "universal" due to Matter so non-compatibility betwixt smarthome ecosystems is (slowly) fading away.
For the doorbell cam, I went with the Aqara smart doorbell. It's not only compatible with the HK ecosystem but it's got local storage as well. HK with iCloud+ give unlimited cameras recording history (for, I think 7 days?) so that's a plus. However, the field of view is wider rather than taller so that may or may not work for you. The other alternative which is good, but gets mixed reviews is the Logitech Circle View doorbell. People have complained that it overheats and that QC is bad as it starts delaminating, but it's mixed on who experiences it.
I would also consider a smart door lock. I used to have a SimpliSafe smart lock that integrated with my SS system but I swapped it out for the Aqara U100 (recently released) and have been TICKLED with it. It's HK compatible (along with other ecosystems) and does, overall, everything. My mom enjoys being able to biometrically open it as well as using our HomeKey if we don't want to use our fingerprint.
For outside cameras, if you're handy enough, you can just get some WyzeCam v3s and bring them into HK via Scrypted. They do have local storage available but since they're outside, it's up to you to determine if that's something you're comfortable with as anyone can just come up and pop the card.
However, if you bring them into HK via Scrypted, you have the option of, once again, recording to iCloud for the 7 days. If the locations you're wanting to watch are near windows (and near outlets), you can put them in window mounts and they can watch the outdoors while being safe inside.
Wyze does have the outdoor v2 if you're needing them to view places where there's no window or power outlets. These require a hub but I think they can be brought into HK via Scrypted as well.