Manually format Task color (not conditional)

Is it possible to manually change a task color without conditional formatting?  Not sure if this is still possible, but I was previously able to create a Custom Form to make a Task color red.  I could then attach this Custom Form to a Task in a Timeline or Timeline Template which would reflect in the Task List. 

Use case: I'd like to make all client-related tasks red (Client Reviews, Client Presentations, etc). 

I'm already aware of conditional formatting, but this would require a rule to be created, ex: Task Names that contain 'Client.'  However, not all tasks that include 'Client' need to be red (ex: Revise based on Client Feedback).  I could do a workaround like including a symbol, such as *, but I want to keep my Task Names clean.  I also don't want to create a series of rules that include specific language in case a PM decides to change the Task Name, or use Task language that doesn't meet the criteria.

Any solutions/ideas?  Thanks in advance!