The symptoms you reported (yellow gel and white/grey liquid consistency of the semen) are completely normal. The semen is a mixture of fluids from several glands together with the spermatozoa.

The yellowish color is from the fluid which is produced from the seminal vesicles.

The prostate produces whitish fluid which contains certain enzymes.

The bulbourethral glands secrete a clear secretion into the lumen of the urethra to lubricate it. As you can see, all the colors you mentioned are simply colors of fluids produced by adequate glands.
You might want to visit your family doctor for additional information.