The only reason why a co-founder makes sense is if you are looking to give away sweat equity in lieu of salary.
The business proposition and founder track record matter more than the size of the team. Even worse, a large team has the risk to be perceived as window dressing if not much has been accomplished thus far.
You will inevitably need to find sweat equity partners as it is increasingly difficult to get financing at interesting valuations if you don't have a working product or some indications from the market that your business model works.
If you have an interesting proposition, you should not have issues in finding people that are willing to work for free in exchange for a piece of the action (or funding without having a large team).
Probably the most important parameter to consider, even ahead of the business valuation itself, are the terms of the investment contracts and/or shareholder agreements.
In many cases, as sophisticated investors (most of them these days) will want you to keep most of the risk, your control question might become moot.
For a start, minority shareholders (it can be you or your investors for that matter) can have minority protection clauses (veto powers for big decisions like additional funding, divestitures or extraordinary dividends) in the shareholder agreement or company bylaws.
Even if you still have control (>50%) right after an investment, founders (or angel investors) can be diluted if management misses their business plan projections (God forbid!) and milestone-based clauses in the investment contract are enforced.
Along the same lines, sorry to keep taking about worst case scenarios, most investors nowadays have anti-dilution provisions that can exacerbate the dilution of the founder round if there is a valuation "adjustment" in the future.
The later means that, to illustrate how anti-dilution provisions work, even if founders had a favourable Series A valuation, the Series A investors will have the right to adjust the original investment to a Series B valuation if the Series A turned out to be overvalued.
In conclusion, as other relevant comments in this posting, you may want to focus your attention on how much funding your business needs in order to grow... and also in a good corporate lawyer.
In addition to all the very good comments I've read, ask them about the process they will follow to work on your project. Be concerned if they don't cover the basics which is doing consumer/customer research to understand who is your target group, understanding what motivates your consumers to buy your products and what makes your company different from others.
In a world where people's attention span is about 5s, having different color schemes would not only contribute to reduce your target's attention span but also create confusion that would annihilate whatever your target remembers about your brand.
Consumers typically accepts different color schemes when having B&W vs color. See the following examples of good color branding.
With the hope that the product will be so addictive to its users, most B2B SaaS companies will allow you to test ride the product before starting to charge you.
However, the answer to your question might depend on some factors and the first one that comes to my mind is the training needed to use the service.
At OneMove Technologies, for instance, the complexity of the program required a 30 min demo to really appreciate what the program might do for its prospective customers.
This can be easily be replaced by a good old video but then the sales reps, who are remunerated with commissions, might get a bit territorial. For them, the easiest way to claim a client is by demoing it.
Even in these cases, smart companies will let you test drive it for a 2 or 3 uses (if billing per use) or for a period of a month (if billing with subscription) before charging customers and adapt their incentive plans accordingly.