flag restoration continued

[kilty55]

hiya ll,i recently took on a job of cleaning up the customers original flagstones which date back to the 1800s,using all the advice given we have clened them all right back to original stones removing paints,varnishes,cement etc,,the flags have come up an assortment of natural clours inc blue,green and red tints..not much natural light penetrates them however as its a basement and tested one with lithofin stain stop as a sealer,,would it be worthwhile applyin lithofin colour enhancer 1st then stain stop as the sealer afterwards?? customer has flags all over the rest of house but most have been newly laid and are black in appearamce i have told her i cant acheive this because of the type of stone we are using so natural colours will have to do. also only 1 more thing i need advice on the flags are butt jointed but are rough/natural looking and some black/brown mix of some sort has been applied right in the centre of 4 flags in middle of floor,i was wanting to remove this as it doesnt look great but am lost as to what to replace it with,it basically is hiding where the 4 stones are broken.