adjective
insipid
in-SIP-id/ɪnˈsɪpɪd/
So weak in flavor as to be unappealing.
The soup tastes insipid until I add salt and herbs.

Etymology
The literal sense is “not tasty,” describing something without perceptible flavor. The figurative sense applies that same lack of flavor to things that offer little interest or liveliness.
In context
they're pale and insipid and they're French and they're tasteless
More examples
- Too much ice leaves the lemonade insipid.
- These pale tomatoes are insipid compared with the garden ones.
- A squeeze of lemon brightens the insipid sauce.
Forms
insipid
insipidity noun — The unappealing quality of lacking flavor.
Similar words
- bland
- Can describe mild flavor without implying that it is unappealing.
- tasteless
- Suggests no detectable flavor, not merely too little flavor.