Weights - NEWBIE please help

Hi

I'm new to this whole strength training thing. I want to gain enough muscle so that I look toned rather than 'muscly'. At the moment I'm using 3kg dumbbells, but I eat at a calorie deficit. Its rare that I go above that. However, my question is eating on a calorie deficit doing more harm than good? Furthermore, is the size of my dumbbells adequate or should I increase the weight?