VP-9000 (ROLAND) Knob Caps

Hi, I am trying to source replacement potentiometer knob caps for the Pitch, Time and Formant controls for the VP-9000. The OEM ones have orange highlights to match the VP-9000 color scheme but I don’t necessarily need them to match. Just want them to look OEM. Are these available? Is there a suitable OEM Roland replacement knob from another synth or sampler from that era? Thanks!