A negative number.  it is a setting you must have set in accounts and settings to show negative numbers in red.

Resolution for 'amount coloured issue: 'what does an amount coloured red and negative indicate' available: Yes.

The amount coloured issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the amount coloured issue yourself by looking for a resolution described in the article. If it is a complex amount coloured issue or you are unable to solve the issue, you may contact us by clicking here or by using other amount coloured support options.

For more information about resolving issues related to amount coloured in Quickbooks/QBO or to get support for the issue 'what does an amount coloured red and negative indicate', click the link below: