The simplest method of control is a sharp stream of water to knock the wee buggers off the plants. Sometimes people will do this and then say the Aphids have "returned" (they don't) when a new generation has appeareed that also needs to be knocked off the same way.

I saved nasturtium seeds of mixed colors, the seeds produced mixed colors, mostly yellows and oranges. I like the red ones too, so this year I will plant Empress of India, which is really more of an orange-ish red, but still pretty and very bright and eye catching. I'm going to save the seed from them too, just to see what I get. Nasturtium seed does come in a lot of beautiful colors now - peach, soft yellow, coral, bright pink but you'll need to buy the seeds to get those colors, I've never had them reseed into anything but oranges and yellows, but its worth a try to save the seeds just to see what they look like.

and yet.. when i googled it.. it said they were annuals.. go figure.... heres the link.. i relied on the first link below the ads ... https://duckduckgo.com/?t=ffcm&q=nasturtium&ia=web further down it says they are annuals and perenials ... whatever ... but it might depend on where OP is.. and which N she wants to grow ... instead of waiting... heres what else i was thinking... if you are getting a jump start on planting them outdoors next spring.. you might try starting see 4 to 6 weeks before they can go outside ... so you have rather young vigorous plants to go out ... if you start too soon indoors.. with the lack of light.. you will end up with etoliated ugly plants.. that will not transplant outside easily ... if you are trying to grow them as house plants... it may or may not work.. depending on light levels as flora noted .. and for sure what she said.. why not experiment.. its just a pack of seeds and some media .. etc .. it will be a nice winter hobby seeing what happens ... ken

Yes @floral_uk z.8/9 SW UK, Phoenix flowers do look different than most other nasturtium flowers and it is my experience that there aren't as many flowers as I see with other varieties of that I grow simultaneously but I do like their unique ability to climb upwards. Here is another Phoenix that I grow on an obelisk (and a close-up of the flowers):