Happens on both 1.21 and 1.22 experimental.
AUR A1 Scope reticle changes color from black to red when aiming at certain spots. Possibly has to do with lighting I assume.
Included below: 2 screenshots and a short video demonstrating the issue
Normal black reticle
Red reticle bug
Video link demonstrating the issue (10 seconds long): https://www.youtube.com/watch?v=g_6wJBPN_yo