Option's Style Menu suffers Crittical Error with color picker boxes.

[CringingCorvid]

I'm using Firefox version 87.0 (64 bit) to play the in-browser Java version of TITS, if it matters.
At any point, including directly after launching the game in browser, upon going to the Options Menu, and selecting Style, the game will crash if you click on any of the colored boxes next to the Hex value box for that option's hue. A small window for trying to pick a color based on a more visual approach is briefly seen hovering over it before the error is thrown.

 Version: 0.69.420-PUBLIC#1732 Message: window.visualViewport is undefined Stack:
o/a.handleClick@https://www.fenoxo.com/play/TiTS/release/main.662372e7.js:1:12025149
We@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:404807
Ye@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:404961
kr/<@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:423146
kr@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:423240
Or@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:423656
Mr/<@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:429304
Fe@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:504776
Mr/<@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:425115
Mr@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:425143
Jt@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:413230
Qt@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:412456
60053/t.unstable_runWithPriority@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:534218
Vo@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:433483
Ne@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:504516
Xt@https://www.fenoxo.com/play/TiTS/release/vendors.0f879145.js:1:412249