I have been trying to decide for quite a while whether to respond further in this thread. I think there remain a couple of points that merit further discussion.
It seems to me that whether one user on their computer can see something well on the screen has little bearing on whether a different user on their computer can see the same thing as well as the first user.
I am reminded particularly of the time when computers were transitioning from CRT monitors to flat screen monitors. I discovered that things that were easy to see on a CRT were sometimes not so easy to see on a flat screen. In particular, sometimes there could be issues with contrast on a flat screen. For example, I had a death certificate where the ink was extremely faded. On a CRT, I could read the death certificate, but only with great difficulty. On a flat screen, I could read the death certificate not at all, even though it was the same JPG file.
I later discovered that I could read the faded death certificate on a flat screen, but only if I tilted the screen at a different angle. In fact, the tilt angle had to be pretty severe where I was looking at the screen almost sideways.
So here is a screen capture of the circles I have been calling invisible. They appear in their original form and also in two additional forms where I have enhanced them. Even if you can see the circles in their original form in my screen capture, that does not mean I always can. I find it very easy to make them disappear and then to reappear just by changing the tilt of the screen very slightly. And even when I can see them, they are very hard to see on my screen with my eyes. The enhanced circles are much easier to see.
The original circles are RGB=(235,235,235) on a background of RGB=(227,227,227). That is not much difference in the contrast. The enhanced contrast circles are RGB=(255,255,255) (pure white) on the same background. I can’t make them disappear entirely by changing the tilt of the screen, but I can make them hard to see by changing the tilt of the screen. The better still circles are RGB=(0,0,0) (pure black) on the same background. Nothing I can do on the screen makes them hard to see.
I find the same lack of contrast to be a problem throughout RM. It’s not just these circles. Dark text is often not dark enough. Light background is often not light enough. And the screen fonts often have very thin lines. This is a very modern look and feel, and RM10 is far from the only app that takes this modern approach. I don’t think it’s a good approach for users with old eyes. I do realize that text that is too dark and backgrounds that are too light and fonts that are too strong can look unprofessional and cause eye strain. But even so, you still need to be able to see what you need to see.