Paid use is based on perceived utility, and donations (to me) go to a perceived need (and if there's utility on top, that's great). This app doesn't cry "I need money to do X", so I'm not sure why the author even expected donations, and "boatloads of traffic" isn't a reason that gets me to donate, really.
>This tool was created to solve my own problem.
You create a very simple tool for yourself that can do exactly one thing and expect people to pay for it? And 4500 site accesses is absolutely nothing, by the way.
The main problem here are your unrealistic expectations.
I contribute to OSS that is used by millions of people. Certainly I should be a millionaire? No, that's not how it works.
I even had a horrifying experience when someone pretended he was donating only to get me to use his cryptocrap. What a f* waste of time that was.
Probably the only ones who can make it out of donations are the best known devs in their fields like Sindre Sorhus . Others, while also really well known, have gone the open-source-but-pay-for-pro route like TJ  and John O'Nolan . Thinking you can live purely of passive donations is, at best, naive.
Here are the statistics of 30k users and 80k page views on my latest project that netted those $10: https://twitter.com/FPresencia/status/955782847230431232
Not getting any customers from DesignerNews is more of a problem, and probably indicates something is wrong with your call(s) to action. They're obviously not working, or your product isn't useful. Ideally you should have set it up to capture user information before launching, because then you'd be in a position to ask the people who visited why they didn't buy. It's a little late for that now.
In 5 years and tens of thousands of downloads I could count on two hands the number of people who had made a donation. Then I put the download link behind a 'pay what you want, including zero' button, and I made more in one month of that than the previous 5 years of donations.
Asking for donations is a poor way to monetize your product.
First off, that's not the right quote. It's "If you build it, HE will come." He being "Shoeless" Joe Jackson, a baseball playing ghost. And if you're basing your marketing strategy on baseball playing ghosts, you need to go back to school. Ghosts don't have any money, they can't buy your product. Baseball playing ghosts didn't even fund the REAL field of dreams, just down the road from me where they filmed the movie. The movie itself brought popularity and prosperity to the field, and since the movie was almost 30 years ago, the field is fallen on hard times.
But lastly, and this bit of insight came from my grandmother: It never amazes me when people offer something for free, and then get mad when people take them up on that offer. You did it. You chose to make it free to use. You put a tip jar out on the counter, sure, but ultimately the thing is free with no strings attached.
You'll hear from me again!
I'm glad to hear that!
And good luck, I'm one of those who love smaller projects submitted on show HN.
Not to disparage your work and your site. It looks great, and your call to action to donate is quite clear, but to me, at first glance, looks like about a half dozen other sites that I have in my bookmarks bar.
Perhaps if you differentiated your site a little more from the others, so that I could see an immediate benefit, then you might be more successful.
Here is a use case that would be an instant hit with me. We are in the process of redesigning our logo for our SaaS app, and along with the redesign/rebranding, I would like to ensure that all the design elements on our web app conform to a similar colour palette.
If I could upload my new logo to your site, and it would magically give me the Bootstrap CSS files for a few alternative colour layouts that take into consideration the Bootstrap .success, .warning, .danger etc. qualifiers, then it would be an instant $10 to $20 pinged across to you from me.
Maybe your site does that? I don't know - a cursory look didn't tell me how it could be of value to me...
Also, getting no donation from 4500 visitors is not really bad nor good. People do not donate often (because you can't donate every time someone ask for a donation).
Nevertheless, that type of 'tool' is too trivial for me to even think about donating. Actually, I still don't know what it is supposed to do. I mean, okay if you don't know how to read hex-colors you can use the normal dev-tools color pickers or some color picker which suggests other fitting colors, but just a tool to visualize and let you change the order of an array of color codes?!? Sounds like something you would write in jsfiddle.
Also anyone with a lick of JS experience could make this in less than an hour.
Also 4500 isn’t a lot.
You seem to be running under the assumption that all or any of those 4,500 users even have any money to give you.
The act of making it doesn't entitle you to turnover....
If you want to give something away, then do just that, give it away expecting nothing in return.
If you want to profit, then build and monetize for that.
Don't expect a middle ground between the two.