For string life with rounds, you judge with your ear. Not by how they look. They will discolor from use. Contact with your hands and exposure to the elements. You can get some string wipes if it bothers you. And it may even slightly extend the tone life.
Superbrights are a pretty easy recommend to try. As mentioned, they are a very flexible variation of hex-core. Tone won't be the same as Sunbeams. But, I think you will like the tone.
Superbrights have an easy to like tone. And when they first released, a lot of people were impressed by the tone. Warm, punchy mids. Articulate low mid. Slightly crunchy high-mid. Relaxed highs. Great for staccato styles.
Of DR strings, I would say the closest tone would be Fat Beams (which sound nothing like you would expect a stainless string to sound).
They also have a smoother feel, much like DR strings. And the way their tone ages also works out well for longevity.
That said, on a short scale bass: strings tend to feel a bit lower tension. So, you may find such a flexible string is too much in that direction.
Nowadays, I play GHS roundcore boomers. They are balanced tension, which sets up better, and feels consistent from string to string.. And while they do still have that slightly supple feel from being roundcore; they don't feel floppy. They have a very positive feel to them.
Different tone from Sunbeams. RC Boomers are low mid focused, crunchy in the mids and high mids. And they really seem to emphasize crunch, rather than warmth.
Sunbeams to me, have a musical high mid purr, balanced mids, A bit light on lows.
Historically, I'm a fan of the kind of Stainless Strings which emphasize complex mids and lows. Rather than being the "brightest" strings. My current overall choice for that would be Stainless DR Low-Riders. And I do have one bass which is only ever strung with those.
Nickel low-riders sound very different.