My first reaction to the Keyforge app this morning was that it was hard to read because of low contrast between the text and the background. This is something I run into often these days, see https://www.wired.com/2016/10/how-the-web-became-unreadable/ for more background information.

You can use the WebAIM tool at https://webaim.org/resources/contrastchecker/ to check contrast ratios and see if they meet Google and Apple's recommended 7:1 contrast ratio, which the W3C also recommends for "normal" text.

Assuming that the app is using the same colors as the web page, deck name colors on their background are:

text: #5A5145
background: #D2CBB9

If you plug that in to the tool, you get 4.81:1, which is below the 7:1 recommended contrast ratio.

It would be great if this could be fixed, it's just two color values and makes the app usable by more people.

https://webaim.org/resources/contrastchecker/?fcolor=5A5145&bcolor=D2CBB9 shows the current colors

https://webaim.org/resources/contrastchecker/?fcolor=383838&bcolor=D2CBB9 makes the ratio 7.25:1, just slightly over 7:1

If you put them both in tabs and flip back and forth you can see the difference. The darker text is significantly more readable for me, it keeps the 'faux parchment' look, and you probably wouldn't notice at all unless someone pointed it out and you were specifically looking.

I think this is great constructive criticism and I hope you have every success in getting this changed.

There is a feedback link on Keyforgegame.com that seems like a good place to go for this sort of thing