For a daylight-balanced flash, carry plus green gels, not a strong fluorescent correction meant primarily for tungsten sources. A good practical choice is to carry light strengths such as 1/4, 1/2, and full plus green, because fluorescent lighting varies and stacking weaker gels lets you fine-tune the effect.

Based on the community answers, Lee 244 Plus Green is the correct family for daylight flash, while lighter versions like 245 (1/2) and 246 (1/4) are often more useful as general-purpose options. You can stack them if needed.

If the fluorescent light is also warmer than daylight, combine plus green with CTO:

• plus green + 1/2 CTO for roughly 3600K fluorescent
• plus green + 1/4 CTO for roughly 4300K fluorescent
• plus green alone for roughly 5700K fluorescent

Avoid a heavy tungsten-to-fluorescent correction gel as your default on flash; it’s likely too strong. Also remember each gel layer reduces flash output somewhat, so compensate exposure/power as needed.