Hi Karnada,
Thank you for posting your question in this community.
If I am understanding correctly, you would like to save your custom shape style or Text boxes in Excel so that you don’t have to readjust the color, effect, size every time since you frequently use them in Excel.
In this scenario, I am afraid it is not feasible with the built-in features of Excel app at this moment. Every time when we insert a shape or Text box we need to manually change its settings or apply the built-in styles under Shape styles. In this case, I suggest you can raise this idea in Excel UserVoice platform, which it can let the related product team be aware of this scenario and improve it with a better solution. Sorry for the inconvenience caused.
However, here is a workaround you may consider, which you can create an Excel file like a template library to store all your frequent used shapes or text boxes you created. Then you can copy and paste the shape or text boxes you costumed based on your demand.
Best regards,
Dihao