No data presumably means the scheduled operation has run, so that limits the icons which are relevant.
If it's not OK that nothing happened — that is, it's failed — then the yellow exclamation mark is the icon to use.
- Scheduled Operation Failed
If it is OK that nothing happened, then the green tick is the icon to use.
- Nothing went wrong
If the scheduled operation did not run, but did not miss its schedule (that is, the scheduled time was reached but it was prevented from running because there was nothing to do and no point in running), then you could use a green circle + tick because the job completed normally with nothing wrong, or a green circle with a different symbol (like a white ring) because nothing is wrong and nothing needed doing.
What the base colour is will depend on the purpose of the chart. If it's important to see a sea of green, then that's what should signify "No error".