In order to observe a clean square wave at 200kHz, the rise-time needs to be around 250ns (about 10% of the pulse width). The sparkfun tutorial shows the clock coupled through a 10k resistor. Now, to get 250ns risetime, you need an RC time constant of 114ns giving a capacitance of about 11pF. So the sum total of the circuit input capacitance, the stray capacitance and critically, your 'scope probe capacitance must be less than 11pF. I reckon this is your problem.
If the waveform looks OK at the driven end of the resistor and the input capacitance of the driven device is low, you might be OK but you won't be able to prove it without a very low capacitance 'scope probe.
Yellow and Red: Film capacitors. Red: Without safety approval. Yellow: With safety approval. (Colors: Just in your case. It's not because of the colors, it's because of the X... markings! Any type may be made in any color!) Depending on the conductor (real film or metallic layer) and dielectric, they feature (very) low ESR and (very) low dissipation factor. Good for switching power applications whenever you need more capacitance than ceramic capacitors can offer. You added the info that the red ones read 100nJ400, which means 100 nF; Tolerance: 5 %; 400 V. Common tolerance codes for capacitors: J = ± 5%; K = ± 10%; M = ± 20%.
Blue, from left to right: 2 x Safety-Rated Ceramic Disc Capacitors. Very low ESR, sometimes with a big tolerance and temperature coefficient, though. The third blue disc from the left appears to be a varistor, not a capacitor. It is labeled 7K471. 7K means it has a disk size of 7 mm (the disk size corresponds to the energy it can absorb) and it starts to conduct at or above "471" = 47*101 V = 470 V. Number four is 221; 1KV (no safety rating visible), meaning 22 * 101 pF = 220 pF; max. voltage 1 kV.
Black: Electrolytic Capacitors. Some bad properties, but you get an awesome C*V product per volume.
Hints on reading the values:
https://electronics.stackexchange.com/a/33454/930
Identifying Capacitors
Hints on the safety ratings: X means you may use these between live and neutral (L and N). This is a critical application because a small leakage path will continuously be fed from the lines and fires may result. I have had one of these fail in a HP function generator last year and the room smelled toxic for weeks, even though I washed out all the stuff left by the smoldering decomposition of the cap - and luckily the design of the cap was of the self-extinguishing type. Y means you may use the caps between L or N and PE. Critical because fires may result for the reason just explained, and because an insulation failure may result in L being connected to the housing (PE). The number behind the X or Y shows the class (good or better). Datasheets will tell you more. Search for X1, X2, Y1 or Y2 and EMI capacitor. EMI because these capacitors are usually used in input filters, often before the fuse, and thus exposed directly the the mains terminals feeding your device.
Best Answer
X2Y capacitors are available from various manufacturers, the MLC structure has three plates, and two of them can be paralleled which cuts back on the ESL (kind of like two inductors in parallel).
The Layout will also affect your application as vias and a few nH of inductance. A spice simulation might help find out how much inductance the circuit can tolerate by adding board and component parasitics.
The voltage rating can be increased with the capacitors in a series configuration if needed but the inductance also increases. A parallel\serial configuration might be solve both problems.
Regular Capacitor parasitics look like this:
simulate this circuit – Schematic created using CircuitLab