Dark Theme Contrast Issue - Payment Requests

[britttttk]

Describe the problem/bug
The default theme used in payment requests is hard to read when using overall Dark Theme mode.

Your environment

• Version of BTCPay Server: BTCPayServer v1.0.4.1
• Deployment method: Debug Regtest

To Reproduce
Steps to reproduce the behavior:

1. Create Payment Request (looks ok)
2. Click Pay now (can't see the invoice and transaction info text very well)
3. Payments completed are also hard to read (see photo below)

Expected behavior
There is more contrast on the payment text in payment requests when using Dark Theme.

Actual behavior
Text is very hard to read.

Screenshots/Links

Additional context
No payment request functionality issues, just viewing payment/transaction text.

[NicolasDorier]

ping @dennisreimann