translucent "waveColor" leads to solid "progressColor" disappearing

[horans]

Bug description

setting "waveColor" with a translucent color(opacity/alpha channel), and setting "progressColor" with a solid color(no opacity/alpha channel), will result in "progressColor" disappearing/missing.
setting both "waveColor" and "progressColor" with solid/translucent color, it's ok.

Environment

• Browser: Chrome v128
• wavefurfer.js v7.8.6

Minimal code snippet

the following code is NOT WORKING:

WaveSurfer.create({
  waveColor: '#00000066',
  progressColor: '#000000'
})

---

the following code WORKS:

WaveSurfer.create({
  waveColor: '#000000',
  progressColor: '#00000066'
})

---

the following code WORKS:

WaveSurfer.create({
  waveColor: '#00000066',
  progressColor: '#33333366'
})

Expected result

"waveColor" and "progressColor" show separately with any color value.

Obtained result

"waveColor" shows, "progressColor" is not showing. (only showing the current frame correctly.)

Screenshots