Brake Fluid Reservoir Schoolboy Error

While cleaning my bike yesterday I was fiddling with the brake fluid reservoir, idly wondering whether to get a nice billet one. Evidently I didn’t do it up properly. Nothing leaked riding to or from work today, until I braked quite hard before turning into the petrol station, after which there was some brake fluid on the front of the tank and steerer area. Wiped it up, tightened the reservoir cap and washed the bike with loads of water and some Muc Off spray when I got home five minutes later. I’m pretty sure I’ve got any fluid spilt cleaned off.

My question is, can I just top up the reservoir with some more DOT4? It’s pretty much on the lower limit line now, so at worst I’ve lost an amount equal to the difference between the upper and lower limits. Bike was serviced in July and I assume fluid replaced (it’s still nice and clear). I don’t know what brand fluid is in there. Any harm in just topping it back up?

 

Cheers, that makes sense!

 

Won’t it just!

 

Cheers