@M03: If you head to Settings > Wallpaper and style > Colour palette > Choose a palette based on colours from your wallpaper (make your selection) > Apply palette to app icons (toggle this option on), does this resolve your issue?
Yes that worked.. why they thought anyone would want that is beyond me 🤦♀️
My icons turned dark and it turns out I had dark mode scheduled that's why. So when I switched it off it went back to lilac. Your phone might be on dark mode 🤔