[Power Run] Improve contrast of the 'start typing' label

[niels9001]

As pointed out by @AnuthaDev in #2988: in light mode, the current foreground color of the 'start typing' label is not meeting accessibility guidelines.

[crutkas]

lets match hint text from textbox for contrast rating

[niels9001]

@crutkas I think this was solved in 0.18 or so? We can close this issue.